diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 79419d3..021fdb5 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -245,6 +245,7 @@
         { OPT,      "events/kmem/ion_heap_shrink/enable" },
         { OPT,      "events/ion/ion_stat/enable" },
         { OPT,      "events/gpu_mem/gpu_mem_total/enable" },
+        { OPT,      "events/fastrpc/fastrpc_dma_stat/enable" },
     } },
     { "thermal",  "Thermal event", 0, {
         { REQ,      "events/thermal/thermal_temperature/enable" },
diff --git a/include/ftl/cast.h b/include/ftl/cast.h
new file mode 100644
index 0000000..ff1b58a
--- /dev/null
+++ b/include/ftl/cast.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <limits>
+#include <type_traits>
+
+#include <ftl/details/cast.h>
+
+namespace android::ftl {
+
+enum class CastSafety { kSafe, kUnderflow, kOverflow };
+
+// Returns whether static_cast<R>(v) is safe, or would result in underflow or overflow.
+//
+//   static_assert(ftl::cast_safety<uint8_t>(-1) == ftl::CastSafety::kUnderflow);
+//   static_assert(ftl::cast_safety<int8_t>(128u) == ftl::CastSafety::kOverflow);
+//
+//   static_assert(ftl::cast_safety<uint32_t>(-.1f) == ftl::CastSafety::kUnderflow);
+//   static_assert(ftl::cast_safety<int32_t>(static_cast<float>(INT32_MAX)) ==
+//                                           ftl::CastSafety::kOverflow);
+//
+//   static_assert(ftl::cast_safety<float>(-DBL_MAX) == ftl::CastSafety::kUnderflow);
+//
+template <typename R, typename T>
+constexpr CastSafety cast_safety(T v) {
+  static_assert(std::is_arithmetic_v<T>);
+  static_assert(std::is_arithmetic_v<R>);
+
+  constexpr bool kFromSigned = std::is_signed_v<T>;
+  constexpr bool kToSigned = std::is_signed_v<R>;
+
+  using details::max_exponent;
+
+  // If the R range contains the T range, then casting is always safe.
+  if constexpr ((kFromSigned == kToSigned && max_exponent<R> >= max_exponent<T>) ||
+                (!kFromSigned && kToSigned && max_exponent<R> > max_exponent<T>)) {
+    return CastSafety::kSafe;
+  }
+
+  using C = std::common_type_t<R, T>;
+
+  if constexpr (kFromSigned) {
+    using L = details::safe_limits<R, T>;
+
+    if constexpr (kToSigned) {
+      // Signed to signed.
+      if (v < L::lowest()) return CastSafety::kUnderflow;
+      return v <= L::max() ? CastSafety::kSafe : CastSafety::kOverflow;
+    } else {
+      // Signed to unsigned.
+      if (v < 0) return CastSafety::kUnderflow;
+      return static_cast<C>(v) <= static_cast<C>(L::max()) ? CastSafety::kSafe
+                                                           : CastSafety::kOverflow;
+    }
+  } else {
+    using L = std::numeric_limits<R>;
+
+    if constexpr (kToSigned) {
+      // Unsigned to signed.
+      return static_cast<C>(v) <= static_cast<C>(L::max()) ? CastSafety::kSafe
+                                                           : CastSafety::kOverflow;
+    } else {
+      // Unsigned to unsigned.
+      return v <= L::max() ? CastSafety::kSafe : CastSafety::kOverflow;
+    }
+  }
+}
+
+}  // namespace android::ftl
diff --git a/include/ftl/details/cast.h b/include/ftl/details/cast.h
new file mode 100644
index 0000000..87b9f1e
--- /dev/null
+++ b/include/ftl/details/cast.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <limits>
+#include <type_traits>
+
+namespace android::ftl::details {
+
+// Exponent whose power of 2 is the (exclusive) upper bound of T.
+template <typename T, typename L = std::numeric_limits<T>>
+constexpr int max_exponent = std::is_floating_point_v<T> ? L::max_exponent : L::digits;
+
+// Extension of std::numeric_limits<T> that reduces the maximum for integral types T such that it
+// has an exact representation for floating-point types F. For example, the maximum int32_t value
+// is 2'147'483'647, but casting it to float commonly rounds up to 2'147'483'650.f, which cannot
+// be safely converted back lest the signed overflow invokes undefined behavior. This pitfall is
+// avoided by clearing the lower (31 - 24 =) 7 bits of precision to 2'147'483'520. Note that the
+// minimum is representable.
+template <typename T, typename F>
+struct safe_limits : std::numeric_limits<T> {
+  static constexpr T max() {
+    using Base = std::numeric_limits<T>;
+
+    if constexpr (std::is_integral_v<T> && std::is_floating_point_v<F>) {
+      // Assume the mantissa is 24 bits for float, or 53 bits for double.
+      using Float = std::numeric_limits<F>;
+      static_assert(Float::is_iec559);
+
+      // If the integer is wider than the mantissa, clear the excess bits of precision.
+      constexpr int kShift = Base::digits - Float::digits;
+      if constexpr (kShift > 0) {
+        using U = std::make_unsigned_t<T>;
+        constexpr U kOne = static_cast<U>(1);
+        return static_cast<U>(Base::max()) & ~((kOne << kShift) - kOne);
+      }
+    }
+
+    return Base::max();
+  }
+};
+
+}  // namespace android::ftl::details
diff --git a/include/ftl/small_map.h b/include/ftl/small_map.h
index 84c15eb..bcaba82 100644
--- a/include/ftl/small_map.h
+++ b/include/ftl/small_map.h
@@ -19,6 +19,7 @@
 #include <ftl/initializer_list.h>
 #include <ftl/small_vector.h>
 
+#include <algorithm>
 #include <functional>
 #include <optional>
 #include <type_traits>
@@ -28,7 +29,10 @@
 
 // Associative container with unique, unordered keys. Unlike std::unordered_map, key-value pairs are
 // stored in contiguous storage for cache efficiency. The map is allocated statically until its size
-// exceeds N, at which point mappings are relocated to dynamic memory.
+// exceeds N, at which point mappings are relocated to dynamic memory. The try_emplace operation has
+// a non-standard analogue try_replace that destructively emplaces. The API also defines an in-place
+// counterpart to insert_or_assign: emplace_or_replace. Lookup is done not via a subscript operator,
+// but immutable getters that can optionally transform the value.
 //
 // SmallMap<K, V, 0> unconditionally allocates on the heap.
 //
@@ -43,16 +47,19 @@
 //   assert(!map.dynamic());
 //
 //   assert(map.contains(123));
-//   assert(map.find(42, [](const std::string& s) { return s.size(); }) == 3u);
+//   assert(map.get(42, [](const std::string& s) { return s.size(); }) == 3u);
 //
-//   const auto opt = map.find(-1);
+//   const auto opt = map.get(-1);
 //   assert(opt);
 //
 //   std::string& ref = *opt;
 //   assert(ref.empty());
 //   ref = "xyz";
 //
-//   assert(map == SmallMap(ftl::init::map(-1, "xyz")(42, "???")(123, "abc")));
+//   map.emplace_or_replace(0, "vanilla", 2u, 3u);
+//   assert(map.dynamic());
+//
+//   assert(map == SmallMap(ftl::init::map(-1, "xyz")(0, "nil")(42, "???")(123, "abc")));
 //
 template <typename K, typename V, std::size_t N>
 class SmallMap final {
@@ -80,12 +87,7 @@
   // The syntax for listing pairs is as follows:
   //
   //   ftl::SmallMap map = ftl::init::map<int, std::string>(123, "abc")(-1)(42, 3u, '?');
-  //
   //   static_assert(std::is_same_v<decltype(map), ftl::SmallMap<int, std::string, 3>>);
-  //   assert(map.size() == 3u);
-  //   assert(map.contains(-1) && map.find(-1)->get().empty());
-  //   assert(map.contains(42) && map.find(42)->get() == "???");
-  //   assert(map.contains(123) && map.find(123)->get() == "abc");
   //
   // The types of the key and value are deduced if the first pair contains exactly two arguments:
   //
@@ -95,7 +97,7 @@
   template <typename U, std::size_t... Sizes, typename... Types>
   SmallMap(InitializerList<U, std::index_sequence<Sizes...>, Types...>&& list)
       : map_(std::move(list)) {
-    // TODO: Enforce unique keys.
+    deduplicate();
   }
 
   size_type max_size() const { return map_.max_size(); }
@@ -115,27 +117,27 @@
 
   // Returns whether a mapping exists for the given key.
   bool contains(const key_type& key) const {
-    return find(key, [](const mapped_type&) {});
+    return get(key, [](const mapped_type&) {});
   }
 
   // Returns a reference to the value for the given key, or std::nullopt if the key was not found.
   //
   //   ftl::SmallMap map = ftl::init::map('a', 'A')('b', 'B')('c', 'C');
   //
-  //   const auto opt = map.find('c');
+  //   const auto opt = map.get('c');
   //   assert(opt == 'C');
   //
   //   char d = 'd';
-  //   const auto ref = map.find('d').value_or(std::ref(d));
+  //   const auto ref = map.get('d').value_or(std::ref(d));
   //   ref.get() = 'D';
   //   assert(d == 'D');
   //
-  auto find(const key_type& key) const -> std::optional<std::reference_wrapper<const mapped_type>> {
-    return find(key, [](const mapped_type& v) { return std::cref(v); });
+  auto get(const key_type& key) const -> std::optional<std::reference_wrapper<const mapped_type>> {
+    return get(key, [](const mapped_type& v) { return std::cref(v); });
   }
 
-  auto find(const key_type& key) -> std::optional<std::reference_wrapper<mapped_type>> {
-    return find(key, [](mapped_type& v) { return std::ref(v); });
+  auto get(const key_type& key) -> std::optional<std::reference_wrapper<mapped_type>> {
+    return get(key, [](mapped_type& v) { return std::ref(v); });
   }
 
   // Returns the result R of a unary operation F on (a constant or mutable reference to) the value
@@ -144,11 +146,11 @@
   //
   //   ftl::SmallMap map = ftl::init::map('a', 'x')('b', 'y')('c', 'z');
   //
-  //   assert(map.find('c', [](char c) { return std::toupper(c); }) == 'Z');
-  //   assert(map.find('c', [](char& c) { c = std::toupper(c); }));
+  //   assert(map.get('c', [](char c) { return std::toupper(c); }) == 'Z');
+  //   assert(map.get('c', [](char& c) { c = std::toupper(c); }));
   //
   template <typename F, typename R = std::invoke_result_t<F, const mapped_type&>>
-  auto find(const key_type& key, F f) const
+  auto get(const key_type& key, F f) const
       -> std::conditional_t<std::is_void_v<R>, bool, std::optional<R>> {
     for (auto& [k, v] : *this) {
       if (k == key) {
@@ -165,12 +167,96 @@
   }
 
   template <typename F>
-  auto find(const key_type& key, F f) {
-    return std::as_const(*this).find(
+  auto get(const key_type& key, F f) {
+    return std::as_const(*this).get(
         key, [&f](const mapped_type& v) { return f(const_cast<mapped_type&>(v)); });
   }
 
+  // Returns an iterator to an existing mapping for the given key, or the end() iterator otherwise.
+  const_iterator find(const key_type& key) const { return const_cast<SmallMap&>(*this).find(key); }
+  iterator find(const key_type& key) { return find(key, begin()); }
+
+  // Inserts a mapping unless it exists. Returns an iterator to the inserted or existing mapping,
+  // and whether the mapping was inserted.
+  //
+  // On emplace, if the map reaches its static or dynamic capacity, then all iterators are
+  // invalidated. Otherwise, only the end() iterator is invalidated.
+  //
+  template <typename... Args>
+  std::pair<iterator, bool> try_emplace(const key_type& key, Args&&... args) {
+    if (const auto it = find(key); it != end()) {
+      return {it, false};
+    }
+
+    auto& ref = map_.emplace_back(std::piecewise_construct, std::forward_as_tuple(key),
+                                  std::forward_as_tuple(std::forward<Args>(args)...));
+    return {&ref, true};
+  }
+
+  // Replaces a mapping if it exists, and returns an iterator to it. Returns the end() iterator
+  // otherwise.
+  //
+  // The value is replaced via move constructor, so type V does not need to define copy/move
+  // assignment, e.g. its data members may be const.
+  //
+  // The arguments may directly or indirectly refer to the mapping being replaced.
+  //
+  // Iterators to the replaced mapping point to its replacement, and others remain valid.
+  //
+  template <typename... Args>
+  iterator try_replace(const key_type& key, Args&&... args) {
+    const auto it = find(key);
+    if (it == end()) return it;
+    map_.replace(it, std::piecewise_construct, std::forward_as_tuple(key),
+                 std::forward_as_tuple(std::forward<Args>(args)...));
+    return it;
+  }
+
+  // In-place counterpart of std::unordered_map's insert_or_assign. Returns true on emplace, or
+  // false on replace.
+  //
+  // The value is emplaced and replaced via move constructor, so type V does not need to define
+  // copy/move assignment, e.g. its data members may be const.
+  //
+  // On emplace, if the map reaches its static or dynamic capacity, then all iterators are
+  // invalidated. Otherwise, only the end() iterator is invalidated. On replace, iterators
+  // to the replaced mapping point to its replacement, and others remain valid.
+  //
+  template <typename... Args>
+  std::pair<iterator, bool> emplace_or_replace(const key_type& key, Args&&... args) {
+    const auto [it, ok] = try_emplace(key, std::forward<Args>(args)...);
+    if (ok) return {it, ok};
+    map_.replace(it, std::piecewise_construct, std::forward_as_tuple(key),
+                 std::forward_as_tuple(std::forward<Args>(args)...));
+    return {it, ok};
+  }
+
+  // Removes a mapping if it exists, and returns whether it did.
+  //
+  // The last() and end() iterators, as well as those to the erased mapping, are invalidated.
+  //
+  bool erase(const key_type& key) { return erase(key, begin()); }
+
  private:
+  iterator find(const key_type& key, iterator first) {
+    return std::find_if(first, end(), [&key](const auto& pair) { return pair.first == key; });
+  }
+
+  bool erase(const key_type& key, iterator first) {
+    const auto it = find(key, first);
+    if (it == end()) return false;
+    map_.unstable_erase(it);
+    return true;
+  }
+
+  void deduplicate() {
+    for (auto it = begin(); it != end();) {
+      if (const auto key = it->first; ++it != end()) {
+        while (erase(key, it));
+      }
+    }
+  }
+
   Map map_;
 };
 
@@ -186,7 +272,7 @@
 
   for (const auto& [k, v] : lhs) {
     const auto& lv = v;
-    if (!rhs.find(k, [&lv](const auto& rv) { return lv == rv; }).value_or(false)) {
+    if (!rhs.get(k, [&lv](const auto& rv) { return lv == rv; }).value_or(false)) {
       return false;
     }
   }
diff --git a/include/ftl/small_vector.h b/include/ftl/small_vector.h
index cb0ae35..0341435 100644
--- a/include/ftl/small_vector.h
+++ b/include/ftl/small_vector.h
@@ -348,7 +348,7 @@
   using Impl::pop_back;
 
   void unstable_erase(iterator it) {
-    if (it != last()) std::iter_swap(it, last());
+    if (it != last()) replace(it, std::move(back()));
     pop_back();
   }
 
diff --git a/include/ftl/string.h b/include/ftl/string.h
new file mode 100644
index 0000000..2d96b06
--- /dev/null
+++ b/include/ftl/string.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cassert>
+#include <charconv>
+#include <limits>
+#include <string>
+#include <string_view>
+#include <type_traits>
+
+namespace android::ftl {
+
+enum class Radix { kBin = 2, kDec = 10, kHex = 16 };
+
+template <typename T>
+struct to_chars_length {
+  static_assert(std::is_integral_v<T>);
+  // Maximum binary digits, plus minus sign and radix prefix.
+  static constexpr std::size_t value = std::numeric_limits<std::make_unsigned_t<T>>::digits + 3;
+};
+
+template <typename T>
+constexpr std::size_t to_chars_length_v = to_chars_length<T>::value;
+
+template <typename T = std::int64_t>
+using to_chars_buffer_t = char[to_chars_length_v<T>];
+
+// Lightweight (not allocating nor sprintf-based) alternative to std::to_string for integers, with
+// optional radix. See also ftl::to_string below.
+//
+//   ftl::to_chars_buffer_t<> buffer;
+//
+//   assert(ftl::to_chars(buffer, 123u) == "123");
+//   assert(ftl::to_chars(buffer, -42, ftl::Radix::kBin) == "-0b101010");
+//   assert(ftl::to_chars(buffer, 0xcafe, ftl::Radix::kHex) == "0xcafe");
+//   assert(ftl::to_chars(buffer, '*', ftl::Radix::kHex) == "0x2a");
+//
+template <typename T, std::size_t N>
+std::string_view to_chars(char (&buffer)[N], T v, Radix radix = Radix::kDec) {
+  static_assert(N >= to_chars_length_v<T>);
+
+  auto begin = buffer + 2;
+  const auto [end, err] = std::to_chars(begin, buffer + N, v, static_cast<int>(radix));
+  assert(err == std::errc());
+
+  if (radix == Radix::kDec) {
+    // TODO: Replace with {begin, end} in C++20.
+    return {begin, static_cast<std::size_t>(end - begin)};
+  }
+
+  const auto prefix = radix == Radix::kBin ? 'b' : 'x';
+  if constexpr (std::is_unsigned_v<T>) {
+    buffer[0] = '0';
+    buffer[1] = prefix;
+  } else {
+    if (*begin == '-') {
+      *buffer = '-';
+    } else {
+      --begin;
+    }
+
+    *begin-- = prefix;
+    *begin = '0';
+  }
+
+  // TODO: Replace with {buffer, end} in C++20.
+  return {buffer, static_cast<std::size_t>(end - buffer)};
+}
+
+// Lightweight (not sprintf-based) alternative to std::to_string for integers, with optional radix.
+//
+//   assert(ftl::to_string(123u) == "123");
+//   assert(ftl::to_string(-42, ftl::Radix::kBin) == "-0b101010");
+//   assert(ftl::to_string(0xcafe, ftl::Radix::kHex) == "0xcafe");
+//   assert(ftl::to_string('*', ftl::Radix::kHex) == "0x2a");
+//
+template <typename T>
+inline std::string to_string(T v, Radix radix = Radix::kDec) {
+  to_chars_buffer_t<T> buffer;
+  return std::string(to_chars(buffer, v, radix));
+}
+
+std::string to_string(bool) = delete;
+std::string to_string(bool, Radix) = delete;
+
+}  // namespace android::ftl
diff --git a/include/input/Input.h b/include/input/Input.h
index cd110e8..cd9b486 100644
--- a/include/input/Input.h
+++ b/include/input/Input.h
@@ -369,8 +369,6 @@
     float getAxisValue(int32_t axis) const;
     status_t setAxisValue(int32_t axis, float value);
 
-    void scale(float globalScale);
-
     // Scale the pointer coordinates according to a global scale and a
     // window scale. The global scale will be applied to TOUCH/TOOL_MAJOR/MINOR
     // axes, however the window scaling will not.
diff --git a/libs/ftl/Android.bp b/libs/ftl/Android.bp
index 2524c5f..3026921 100644
--- a/libs/ftl/Android.bp
+++ b/libs/ftl/Android.bp
@@ -14,12 +14,14 @@
         address: true,
     },
     srcs: [
+        "cast_test.cpp",
         "Flags_test.cpp",
         "future_test.cpp",
         "NamedEnum_test.cpp",
         "small_map_test.cpp",
         "small_vector_test.cpp",
         "static_vector_test.cpp",
+        "string_test.cpp",
     ],
     cflags: [
         "-Wall",
diff --git a/libs/ftl/cast_test.cpp b/libs/ftl/cast_test.cpp
new file mode 100644
index 0000000..2abcb8f
--- /dev/null
+++ b/libs/ftl/cast_test.cpp
@@ -0,0 +1,200 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ftl/cast.h>
+#include <gtest/gtest.h>
+
+#include <cfloat>
+#include <cmath>
+#include <limits>
+
+namespace android::test {
+
+using ftl::cast_safety;
+using ftl::CastSafety;
+
+template <typename T>
+constexpr T min = std::numeric_limits<T>::lowest();
+
+template <typename T>
+constexpr T max = std::numeric_limits<T>::max();
+
+template <typename T>
+constexpr T inf = std::numeric_limits<T>::infinity();
+
+template <typename T>
+constexpr T NaN = std::numeric_limits<T>::quiet_NaN();
+
+// Keep in sync with example usage in header file.
+
+static_assert(cast_safety<uint8_t>(-1) == CastSafety::kUnderflow);
+static_assert(cast_safety<int8_t>(128u) == CastSafety::kOverflow);
+
+static_assert(cast_safety<uint32_t>(-.1f) == CastSafety::kUnderflow);
+static_assert(cast_safety<int32_t>(static_cast<float>(INT32_MAX)) == CastSafety::kOverflow);
+
+static_assert(cast_safety<float>(-DBL_MAX) == CastSafety::kUnderflow);
+
+// Unsigned to unsigned.
+
+static_assert(cast_safety<uint8_t>(0u) == CastSafety::kSafe);
+static_assert(cast_safety<uint16_t>(max<uint8_t>) == CastSafety::kSafe);
+static_assert(cast_safety<uint8_t>(static_cast<uint32_t>(max<uint8_t>)) == CastSafety::kSafe);
+
+static_assert(cast_safety<uint32_t>(max<uint64_t>) == CastSafety::kOverflow);
+static_assert(cast_safety<uint8_t>(static_cast<uint32_t>(max<uint8_t>) + 1) ==
+              CastSafety::kOverflow);
+
+// Unsigned to signed.
+
+static_assert(cast_safety<int16_t>(0u) == CastSafety::kSafe);
+static_assert(cast_safety<int16_t>(max<uint8_t>) == CastSafety::kSafe);
+static_assert(cast_safety<int16_t>(max<uint16_t>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<int64_t>(static_cast<uint64_t>(max<int64_t>) - 1) == CastSafety::kSafe);
+static_assert(cast_safety<int64_t>(static_cast<uint64_t>(max<int64_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int64_t>(static_cast<uint64_t>(max<int64_t>) + 1) ==
+              CastSafety::kOverflow);
+
+// Signed to unsigned.
+
+static_assert(cast_safety<uint16_t>(0) == CastSafety::kSafe);
+static_assert(cast_safety<uint16_t>(max<int8_t>) == CastSafety::kSafe);
+static_assert(cast_safety<uint16_t>(max<int16_t>) == CastSafety::kSafe);
+
+static_assert(cast_safety<uint32_t>(-1) == CastSafety::kUnderflow);
+static_assert(cast_safety<uint32_t>(max<int64_t>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<uint32_t>(static_cast<int64_t>(max<uint32_t>) - 1) == CastSafety::kSafe);
+static_assert(cast_safety<uint32_t>(static_cast<int64_t>(max<uint32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<uint32_t>(static_cast<int64_t>(max<uint32_t>) + 1) ==
+              CastSafety::kOverflow);
+
+// Signed to signed.
+
+static_assert(cast_safety<int8_t>(-129) == CastSafety::kUnderflow);
+static_assert(cast_safety<int8_t>(-128) == CastSafety::kSafe);
+static_assert(cast_safety<int8_t>(127) == CastSafety::kSafe);
+static_assert(cast_safety<int8_t>(128) == CastSafety::kOverflow);
+
+static_assert(cast_safety<int32_t>(static_cast<int64_t>(min<int32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int32_t>(static_cast<int64_t>(max<int32_t>)) == CastSafety::kSafe);
+
+static_assert(cast_safety<int16_t>(min<int32_t>) == CastSafety::kUnderflow);
+static_assert(cast_safety<int32_t>(max<int64_t>) == CastSafety::kOverflow);
+
+// Float to float.
+
+static_assert(cast_safety<double>(max<float>) == CastSafety::kSafe);
+static_assert(cast_safety<double>(min<float>) == CastSafety::kSafe);
+
+static_assert(cast_safety<float>(min<double>) == CastSafety::kUnderflow);
+static_assert(cast_safety<float>(max<double>) == CastSafety::kOverflow);
+
+TEST(CastSafety, FloatToFloat) {
+  EXPECT_EQ(cast_safety<float>(std::nexttoward(static_cast<double>(min<float>), min<double>)),
+            CastSafety::kUnderflow);
+  EXPECT_EQ(cast_safety<float>(std::nexttoward(static_cast<double>(max<float>), max<double>)),
+            CastSafety::kOverflow);
+}
+
+// Unsigned to float.
+
+static_assert(cast_safety<float>(0u) == CastSafety::kSafe);
+static_assert(cast_safety<float>(max<uint64_t>) == CastSafety::kSafe);
+
+static_assert(cast_safety<double>(0u) == CastSafety::kSafe);
+static_assert(cast_safety<double>(max<uint64_t>) == CastSafety::kSafe);
+
+// Signed to float.
+
+static_assert(cast_safety<float>(min<int64_t>) == CastSafety::kSafe);
+static_assert(cast_safety<float>(max<int64_t>) == CastSafety::kSafe);
+
+static_assert(cast_safety<double>(min<int64_t>) == CastSafety::kSafe);
+static_assert(cast_safety<double>(max<int64_t>) == CastSafety::kSafe);
+
+// Float to unsigned.
+
+static_assert(cast_safety<uint32_t>(0.f) == CastSafety::kSafe);
+static_assert(cast_safety<uint32_t>(min<float>) == CastSafety::kUnderflow);
+static_assert(cast_safety<uint32_t>(max<float>) == CastSafety::kOverflow);
+static_assert(cast_safety<uint32_t>(-.1f) == CastSafety::kUnderflow);
+
+static_assert(cast_safety<uint16_t>(-inf<float>) == CastSafety::kUnderflow);
+static_assert(cast_safety<uint32_t>(inf<float>) == CastSafety::kOverflow);
+static_assert(cast_safety<uint64_t>(NaN<float>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<uint32_t>(static_cast<float>(max<int32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<uint32_t>(static_cast<float>(max<uint32_t>)) == CastSafety::kOverflow);
+static_assert(cast_safety<uint32_t>(static_cast<double>(max<int32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<uint32_t>(static_cast<double>(max<uint32_t>)) == CastSafety::kSafe);
+
+static_assert(cast_safety<uint64_t>(0.0) == CastSafety::kSafe);
+static_assert(cast_safety<uint64_t>(min<double>) == CastSafety::kUnderflow);
+static_assert(cast_safety<uint64_t>(max<double>) == CastSafety::kOverflow);
+static_assert(cast_safety<uint64_t>(-.1) == CastSafety::kUnderflow);
+
+static_assert(cast_safety<uint64_t>(static_cast<float>(max<int64_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<uint64_t>(static_cast<float>(max<uint64_t>)) == CastSafety::kOverflow);
+static_assert(cast_safety<uint64_t>(static_cast<double>(max<int64_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<uint64_t>(static_cast<double>(max<uint64_t>)) == CastSafety::kOverflow);
+
+// Float to signed.
+
+static_assert(cast_safety<int32_t>(0.f) == CastSafety::kSafe);
+static_assert(cast_safety<int32_t>(min<float>) == CastSafety::kUnderflow);
+static_assert(cast_safety<int32_t>(max<float>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<int16_t>(-inf<double>) == CastSafety::kUnderflow);
+static_assert(cast_safety<int32_t>(inf<double>) == CastSafety::kOverflow);
+static_assert(cast_safety<int64_t>(NaN<double>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<int32_t>(static_cast<float>(min<int32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int32_t>(static_cast<float>(max<int32_t>)) == CastSafety::kOverflow);
+static_assert(cast_safety<int32_t>(static_cast<double>(min<int32_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int32_t>(static_cast<double>(max<int32_t>)) == CastSafety::kSafe);
+
+static_assert(cast_safety<int64_t>(0.0) == CastSafety::kSafe);
+static_assert(cast_safety<int64_t>(min<double>) == CastSafety::kUnderflow);
+static_assert(cast_safety<int64_t>(max<double>) == CastSafety::kOverflow);
+
+static_assert(cast_safety<int64_t>(static_cast<float>(min<int64_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int64_t>(static_cast<float>(max<int64_t>)) == CastSafety::kOverflow);
+static_assert(cast_safety<int64_t>(static_cast<double>(min<int64_t>)) == CastSafety::kSafe);
+static_assert(cast_safety<int64_t>(static_cast<double>(max<int64_t>)) == CastSafety::kOverflow);
+
+TEST(CastSafety, FloatToSigned) {
+  constexpr int32_t kMax = ftl::details::safe_limits<int32_t, float>::max();
+  static_assert(kMax == 2'147'483'520);
+  EXPECT_EQ(kMax, static_cast<int32_t>(std::nexttowardf(max<int32_t>, 0)));
+
+  EXPECT_EQ(cast_safety<int32_t>(std::nexttowardf(min<int32_t>, 0)), CastSafety::kSafe);
+  EXPECT_EQ(cast_safety<int32_t>(std::nexttowardf(max<int32_t>, 0)), CastSafety::kSafe);
+  EXPECT_EQ(cast_safety<int64_t>(std::nexttoward(min<int64_t>, 0)), CastSafety::kSafe);
+  EXPECT_EQ(cast_safety<int64_t>(std::nexttoward(max<int64_t>, 0)), CastSafety::kSafe);
+
+  EXPECT_EQ(cast_safety<int32_t>(std::nexttowardf(min<int32_t>, min<float>)),
+            CastSafety::kUnderflow);
+  EXPECT_EQ(cast_safety<int32_t>(std::nexttowardf(max<int32_t>, max<float>)),
+            CastSafety::kOverflow);
+  EXPECT_EQ(cast_safety<int64_t>(std::nexttoward(min<int64_t>, min<double>)),
+            CastSafety::kUnderflow);
+  EXPECT_EQ(cast_safety<int64_t>(std::nexttoward(max<int64_t>, max<double>)),
+            CastSafety::kOverflow);
+}
+
+}  // namespace android::test
diff --git a/libs/ftl/small_map_test.cpp b/libs/ftl/small_map_test.cpp
index 323b9f9..2e81022 100644
--- a/libs/ftl/small_map_test.cpp
+++ b/libs/ftl/small_map_test.cpp
@@ -18,6 +18,9 @@
 #include <gtest/gtest.h>
 
 #include <cctype>
+#include <string>
+
+using namespace std::string_literals;
 
 namespace android::test {
 
@@ -35,16 +38,19 @@
 
   EXPECT_TRUE(map.contains(123));
 
-  EXPECT_EQ(map.find(42, [](const std::string& s) { return s.size(); }), 3u);
+  EXPECT_EQ(map.get(42, [](const std::string& s) { return s.size(); }), 3u);
 
-  const auto opt = map.find(-1);
+  const auto opt = map.get(-1);
   ASSERT_TRUE(opt);
 
   std::string& ref = *opt;
   EXPECT_TRUE(ref.empty());
   ref = "xyz";
 
-  EXPECT_EQ(map, SmallMap(ftl::init::map(-1, "xyz")(42, "???")(123, "abc")));
+  map.emplace_or_replace(0, "vanilla", 2u, 3u);
+  EXPECT_TRUE(map.dynamic());
+
+  EXPECT_EQ(map, SmallMap(ftl::init::map(-1, "xyz")(0, "nil")(42, "???")(123, "abc")));
 }
 
 TEST(SmallMap, Construct) {
@@ -90,42 +96,253 @@
   }
 }
 
+TEST(SmallMap, UniqueKeys) {
+  {
+    // Duplicate mappings are discarded.
+    const SmallMap map = ftl::init::map<int, float>(1)(2)(3)(2)(3)(1)(3)(2)(1);
+
+    EXPECT_EQ(map.size(), 3u);
+    EXPECT_EQ(map.max_size(), 9u);
+
+    using Map = decltype(map);
+    EXPECT_EQ(map, Map(ftl::init::map(1, 0.f)(2, 0.f)(3, 0.f)));
+  }
+  {
+    // Duplicate mappings may be reordered.
+    const SmallMap map = ftl::init::map('a', 'A')(
+        'b', 'B')('b')('b')('c', 'C')('a')('d')('c')('e', 'E')('d', 'D')('a')('f', 'F');
+
+    EXPECT_EQ(map.size(), 6u);
+    EXPECT_EQ(map.max_size(), 12u);
+
+    using Map = decltype(map);
+    EXPECT_EQ(map, Map(ftl::init::map('a', 'A')('b', 'B')('c', 'C')('d', 'D')('e', 'E')('f', 'F')));
+  }
+}
+
 TEST(SmallMap, Find) {
   {
     // Constant reference.
-    const ftl::SmallMap map = ftl::init::map('a', 'A')('b', 'B')('c', 'C');
+    const SmallMap map = ftl::init::map('a', 'A')('b', 'B')('c', 'C');
 
-    const auto opt = map.find('b');
+    const auto opt = map.get('b');
     EXPECT_EQ(opt, 'B');
 
     const char d = 'D';
-    const auto ref = map.find('d').value_or(std::cref(d));
+    const auto ref = map.get('d').value_or(std::cref(d));
     EXPECT_EQ(ref.get(), 'D');
   }
   {
     // Mutable reference.
-    ftl::SmallMap map = ftl::init::map('a', 'A')('b', 'B')('c', 'C');
+    SmallMap map = ftl::init::map('a', 'A')('b', 'B')('c', 'C');
 
-    const auto opt = map.find('c');
+    const auto opt = map.get('c');
     EXPECT_EQ(opt, 'C');
 
     char d = 'd';
-    const auto ref = map.find('d').value_or(std::ref(d));
+    const auto ref = map.get('d').value_or(std::ref(d));
     ref.get() = 'D';
     EXPECT_EQ(d, 'D');
   }
   {
     // Constant unary operation.
-    const ftl::SmallMap map = ftl::init::map('a', 'x')('b', 'y')('c', 'z');
-    EXPECT_EQ(map.find('c', [](char c) { return std::toupper(c); }), 'Z');
+    const SmallMap map = ftl::init::map('a', 'x')('b', 'y')('c', 'z');
+    EXPECT_EQ(map.get('c', [](char c) { return std::toupper(c); }), 'Z');
   }
   {
     // Mutable unary operation.
-    ftl::SmallMap map = ftl::init::map('a', 'x')('b', 'y')('c', 'z');
-    EXPECT_TRUE(map.find('c', [](char& c) { c = std::toupper(c); }));
+    SmallMap map = ftl::init::map('a', 'x')('b', 'y')('c', 'z');
+    EXPECT_TRUE(map.get('c', [](char& c) { c = std::toupper(c); }));
 
     EXPECT_EQ(map, SmallMap(ftl::init::map('c', 'Z')('b', 'y')('a', 'x')));
   }
 }
 
+TEST(SmallMap, TryEmplace) {
+  SmallMap<int, std::string, 3> map;
+  using Pair = decltype(map)::value_type;
+
+  {
+    const auto [it, ok] = map.try_emplace(123, "abc");
+    ASSERT_TRUE(ok);
+    EXPECT_EQ(*it, Pair(123, "abc"s));
+  }
+  {
+    const auto [it, ok] = map.try_emplace(42, 3u, '?');
+    ASSERT_TRUE(ok);
+    EXPECT_EQ(*it, Pair(42, "???"s));
+  }
+  {
+    const auto [it, ok] = map.try_emplace(-1);
+    ASSERT_TRUE(ok);
+    EXPECT_EQ(*it, Pair(-1, std::string()));
+    EXPECT_FALSE(map.dynamic());
+  }
+  {
+    // Insertion fails if mapping exists.
+    const auto [it, ok] = map.try_emplace(42, "!!!");
+    EXPECT_FALSE(ok);
+    EXPECT_EQ(*it, Pair(42, "???"));
+    EXPECT_FALSE(map.dynamic());
+  }
+  {
+    // Insertion at capacity promotes the map.
+    const auto [it, ok] = map.try_emplace(999, "xyz");
+    ASSERT_TRUE(ok);
+    EXPECT_EQ(*it, Pair(999, "xyz"));
+    EXPECT_TRUE(map.dynamic());
+  }
+
+  EXPECT_EQ(map, SmallMap(ftl::init::map(-1, ""s)(42, "???"s)(123, "abc"s)(999, "xyz"s)));
+}
+
+namespace {
+
+// The mapped type does not require a copy/move assignment operator.
+struct String {
+  template <typename... Args>
+  String(Args... args) : str(args...) {}
+  const std::string str;
+
+  bool operator==(const String& other) const { return other.str == str; }
+};
+
+}  // namespace
+
+TEST(SmallMap, TryReplace) {
+  SmallMap<int, String, 3> map = ftl::init::map(1, "a")(2, "B");
+  using Pair = decltype(map)::value_type;
+
+  {
+    // Replacing fails unless mapping exists.
+    const auto it = map.try_replace(3, "c");
+    EXPECT_EQ(it, map.end());
+  }
+  {
+    // Replacement arguments can refer to the replaced mapping.
+    const auto ref = map.get(2, [](const auto& s) { return s.str[0]; });
+    ASSERT_TRUE(ref);
+
+    // Construct std::string from one character.
+    const auto it = map.try_replace(2, 1u, static_cast<char>(std::tolower(*ref)));
+    ASSERT_NE(it, map.end());
+    EXPECT_EQ(*it, Pair(2, "b"));
+  }
+
+  EXPECT_FALSE(map.dynamic());
+  EXPECT_TRUE(map.try_emplace(3, "abc").second);
+  EXPECT_TRUE(map.try_emplace(4, "d").second);
+  EXPECT_TRUE(map.dynamic());
+
+  {
+    // Replacing fails unless mapping exists.
+    const auto it = map.try_replace(5, "e");
+    EXPECT_EQ(it, map.end());
+  }
+  {
+    // Replacement arguments can refer to the replaced mapping.
+    const auto ref = map.get(3);
+    ASSERT_TRUE(ref);
+
+    // Construct std::string from substring.
+    const auto it = map.try_replace(3, ref->get().str, 2u, 1u);
+    ASSERT_NE(it, map.end());
+    EXPECT_EQ(*it, Pair(3, "c"));
+  }
+
+  EXPECT_EQ(map, SmallMap(ftl::init::map(4, "d"s)(3, "c"s)(2, "b"s)(1, "a"s)));
+}
+
+TEST(SmallMap, EmplaceOrReplace) {
+  SmallMap<int, String, 3> map = ftl::init::map(1, "a")(2, "B");
+  using Pair = decltype(map)::value_type;
+
+  {
+    // New mapping is emplaced.
+    const auto [it, emplace] = map.emplace_or_replace(3, "c");
+    EXPECT_TRUE(emplace);
+    EXPECT_EQ(*it, Pair(3, "c"));
+  }
+  {
+    // Replacement arguments can refer to the replaced mapping.
+    const auto ref = map.get(2, [](const auto& s) { return s.str[0]; });
+    ASSERT_TRUE(ref);
+
+    // Construct std::string from one character.
+    const auto [it, emplace] = map.emplace_or_replace(2, 1u, static_cast<char>(std::tolower(*ref)));
+    EXPECT_FALSE(emplace);
+    EXPECT_EQ(*it, Pair(2, "b"));
+  }
+
+  EXPECT_FALSE(map.dynamic());
+  EXPECT_FALSE(map.emplace_or_replace(3, "abc").second);  // Replace.
+  EXPECT_TRUE(map.emplace_or_replace(4, "d").second);     // Emplace.
+  EXPECT_TRUE(map.dynamic());
+
+  {
+    // New mapping is emplaced.
+    const auto [it, emplace] = map.emplace_or_replace(5, "e");
+    EXPECT_TRUE(emplace);
+    EXPECT_EQ(*it, Pair(5, "e"));
+  }
+  {
+    // Replacement arguments can refer to the replaced mapping.
+    const auto ref = map.get(3);
+    ASSERT_TRUE(ref);
+
+    // Construct std::string from substring.
+    const auto [it, emplace] = map.emplace_or_replace(3, ref->get().str, 2u, 1u);
+    EXPECT_FALSE(emplace);
+    EXPECT_EQ(*it, Pair(3, "c"));
+  }
+
+  EXPECT_EQ(map, SmallMap(ftl::init::map(5, "e"s)(4, "d"s)(3, "c"s)(2, "b"s)(1, "a"s)));
+}
+
+TEST(SmallMap, Erase) {
+  {
+    SmallMap map = ftl::init::map(1, '1')(2, '2')(3, '3')(4, '4');
+    EXPECT_FALSE(map.dynamic());
+
+    EXPECT_FALSE(map.erase(0));  // Key not found.
+
+    EXPECT_TRUE(map.erase(2));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(1, '1')(3, '3')(4, '4')));
+
+    EXPECT_TRUE(map.erase(1));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(3, '3')(4, '4')));
+
+    EXPECT_TRUE(map.erase(4));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(3, '3')));
+
+    EXPECT_TRUE(map.erase(3));
+    EXPECT_FALSE(map.erase(3));  // Key not found.
+
+    EXPECT_TRUE(map.empty());
+    EXPECT_FALSE(map.dynamic());
+  }
+  {
+    SmallMap map = ftl::init::map(1, '1')(2, '2')(3, '3');
+    map.try_emplace(4, '4');
+    EXPECT_TRUE(map.dynamic());
+
+    EXPECT_FALSE(map.erase(0));  // Key not found.
+
+    EXPECT_TRUE(map.erase(2));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(1, '1')(3, '3')(4, '4')));
+
+    EXPECT_TRUE(map.erase(1));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(3, '3')(4, '4')));
+
+    EXPECT_TRUE(map.erase(4));
+    EXPECT_EQ(map, SmallMap(ftl::init::map(3, '3')));
+
+    EXPECT_TRUE(map.erase(3));
+    EXPECT_FALSE(map.erase(3));  // Key not found.
+
+    EXPECT_TRUE(map.empty());
+    EXPECT_TRUE(map.dynamic());
+  }
+}
+
 }  // namespace android::test
diff --git a/libs/ftl/string_test.cpp b/libs/ftl/string_test.cpp
new file mode 100644
index 0000000..f3d85c8
--- /dev/null
+++ b/libs/ftl/string_test.cpp
@@ -0,0 +1,187 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ftl/string.h>
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <cstdint>
+#include <iterator>
+#include <limits>
+#include <sstream>
+#include <type_traits>
+
+namespace android::test {
+
+// Keep in sync with example usage in header file.
+TEST(String, ToChars) {
+  ftl::to_chars_buffer_t<> buffer;
+
+  EXPECT_EQ(ftl::to_chars(buffer, 123u), "123");
+  EXPECT_EQ(ftl::to_chars(buffer, -42, ftl::Radix::kBin), "-0b101010");
+  EXPECT_EQ(ftl::to_chars(buffer, 0xcafe, ftl::Radix::kHex), "0xcafe");
+  EXPECT_EQ(ftl::to_chars(buffer, '*', ftl::Radix::kHex), "0x2a");
+}
+
+namespace {
+
+template <typename F, typename T>
+void ToCharsTest() {
+  constexpr auto kRadix = F::kRadix;
+
+  using Limits = std::numeric_limits<T>;
+  constexpr auto kMin = Limits::min();
+  constexpr auto kMax = Limits::max();
+  constexpr auto kNeg = static_cast<T>(-42);
+  constexpr auto kPos = static_cast<T>(123);
+
+  ftl::to_chars_buffer_t<T> buffer;
+
+  EXPECT_EQ(ftl::to_chars(buffer, kMin, kRadix), F{}(kMin));
+  EXPECT_EQ(ftl::to_chars(buffer, kMax, kRadix), F{}(kMax));
+  EXPECT_EQ(ftl::to_chars(buffer, kNeg, kRadix), F{}(kNeg));
+  EXPECT_EQ(ftl::to_chars(buffer, kPos, kRadix), F{}(kPos));
+}
+
+template <typename...>
+struct Types {};
+
+template <typename F, typename Types>
+struct ToCharsTests;
+
+template <typename F, typename T, typename... Ts>
+struct ToCharsTests<F, Types<T, Ts...>> {
+  static void test() {
+    ToCharsTest<F, T>();
+    ToCharsTests<F, Types<Ts...>>::test();
+  }
+};
+
+template <typename F>
+struct ToCharsTests<F, Types<>> {
+  static void test() {}
+};
+
+template <typename T, typename U = std::make_unsigned_t<T>>
+U to_unsigned(std::ostream& stream, T v) {
+  if (std::is_same_v<T, U>) return v;
+
+  if (v < 0) {
+    stream << '-';
+    return std::numeric_limits<U>::max() - static_cast<U>(v) + 1;
+  } else {
+    return static_cast<U>(v);
+  }
+}
+
+struct Bin {
+  static constexpr auto kRadix = ftl::Radix::kBin;
+
+  template <typename T>
+  std::string operator()(T v) const {
+    std::ostringstream stream;
+    auto u = to_unsigned(stream, v);
+    stream << "0b";
+
+    if (u == 0) {
+      stream << 0;
+    } else {
+      std::ostringstream digits;
+      do {
+        digits << (u & 1);
+      } while (u >>= 1);
+
+      const auto str = digits.str();
+      std::copy(str.rbegin(), str.rend(), std::ostream_iterator<char>(stream));
+    }
+
+    return stream.str();
+  }
+};
+
+struct Dec {
+  static constexpr auto kRadix = ftl::Radix::kDec;
+
+  template <typename T>
+  std::string operator()(T v) const {
+    return std::to_string(v);
+  }
+};
+
+struct Hex {
+  static constexpr auto kRadix = ftl::Radix::kHex;
+
+  template <typename T>
+  std::string operator()(T v) const {
+    std::ostringstream stream;
+    const auto u = to_unsigned(stream, v);
+    stream << "0x" << std::hex << std::nouppercase;
+    stream << (sizeof(T) == 1 ? static_cast<unsigned>(u) : u);
+    return stream.str();
+  }
+};
+
+using IntegerTypes =
+    Types<char, unsigned char, signed char, std::uint8_t, std::uint16_t, std::uint32_t,
+          std::uint64_t, std::int8_t, std::int16_t, std::int32_t, std::int64_t>;
+
+}  // namespace
+
+TEST(String, ToCharsBin) {
+  ToCharsTests<Bin, IntegerTypes>::test();
+
+  {
+    const std::uint8_t x = 0b1111'1111;
+    ftl::to_chars_buffer_t<decltype(x)> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, x, ftl::Radix::kBin), "0b11111111");
+  }
+  {
+    const std::int16_t x = -0b1000'0000'0000'0000;
+    ftl::to_chars_buffer_t<decltype(x)> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, x, ftl::Radix::kBin), "-0b1000000000000000");
+  }
+}
+
+TEST(String, ToCharsDec) {
+  ToCharsTests<Dec, IntegerTypes>::test();
+
+  {
+    const std::uint32_t x = UINT32_MAX;
+    ftl::to_chars_buffer_t<decltype(x)> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, x), "4294967295");
+  }
+  {
+    const std::int32_t x = INT32_MIN;
+    ftl::to_chars_buffer_t<decltype(x)> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, x), "-2147483648");
+  }
+}
+
+TEST(String, ToCharsHex) {
+  ToCharsTests<Hex, IntegerTypes>::test();
+
+  {
+    const std::uint16_t x = 0xfade;
+    ftl::to_chars_buffer_t<decltype(x)> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, x, ftl::Radix::kHex), "0xfade");
+  }
+  {
+    ftl::to_chars_buffer_t<> buffer;
+    EXPECT_EQ(ftl::to_chars(buffer, INT64_MIN, ftl::Radix::kHex), "-0x8000000000000000");
+  }
+}
+
+}  // namespace android::test
diff --git a/libs/graphicsenv/GraphicsEnv.cpp b/libs/graphicsenv/GraphicsEnv.cpp
index d54de49..7f0cac5 100644
--- a/libs/graphicsenv/GraphicsEnv.cpp
+++ b/libs/graphicsenv/GraphicsEnv.cpp
@@ -343,80 +343,6 @@
     return nullptr;
 }
 
-bool GraphicsEnv::checkAngleRules(void* so) {
-    auto manufacturer = base::GetProperty("ro.product.manufacturer", "UNSET");
-    auto model = base::GetProperty("ro.product.model", "UNSET");
-
-    auto ANGLEGetFeatureSupportUtilAPIVersion =
-            (fpANGLEGetFeatureSupportUtilAPIVersion)dlsym(so,
-                                                          "ANGLEGetFeatureSupportUtilAPIVersion");
-
-    if (!ANGLEGetFeatureSupportUtilAPIVersion) {
-        ALOGW("Cannot find ANGLEGetFeatureSupportUtilAPIVersion function");
-        return false;
-    }
-
-    // Negotiate the interface version by requesting most recent known to the platform
-    unsigned int versionToUse = CURRENT_ANGLE_API_VERSION;
-    if (!(ANGLEGetFeatureSupportUtilAPIVersion)(&versionToUse)) {
-        ALOGW("Cannot use ANGLE feature-support library, it is older than supported by EGL, "
-              "requested version %u",
-              versionToUse);
-        return false;
-    }
-
-    // Add and remove versions below as needed
-    bool useAngle = false;
-    switch (versionToUse) {
-        case 2: {
-            ALOGV("Using version %d of ANGLE feature-support library", versionToUse);
-            void* rulesHandle = nullptr;
-            int rulesVersion = 0;
-            void* systemInfoHandle = nullptr;
-
-            // Get the symbols for the feature-support-utility library:
-#define GET_SYMBOL(symbol)                                                 \
-    fp##symbol symbol = (fp##symbol)dlsym(so, #symbol);                    \
-    if (!symbol) {                                                         \
-        ALOGW("Cannot find " #symbol " in ANGLE feature-support library"); \
-        break;                                                             \
-    }
-            GET_SYMBOL(ANGLEAndroidParseRulesString);
-            GET_SYMBOL(ANGLEGetSystemInfo);
-            GET_SYMBOL(ANGLEAddDeviceInfoToSystemInfo);
-            GET_SYMBOL(ANGLEShouldBeUsedForApplication);
-            GET_SYMBOL(ANGLEFreeRulesHandle);
-            GET_SYMBOL(ANGLEFreeSystemInfoHandle);
-
-            // Parse the rules, obtain the SystemInfo, and evaluate the
-            // application against the rules:
-            if (!(ANGLEAndroidParseRulesString)(mRulesBuffer.data(), &rulesHandle, &rulesVersion)) {
-                ALOGW("ANGLE feature-support library cannot parse rules file");
-                break;
-            }
-            if (!(ANGLEGetSystemInfo)(&systemInfoHandle)) {
-                ALOGW("ANGLE feature-support library cannot obtain SystemInfo");
-                break;
-            }
-            if (!(ANGLEAddDeviceInfoToSystemInfo)(manufacturer.c_str(), model.c_str(),
-                                                  systemInfoHandle)) {
-                ALOGW("ANGLE feature-support library cannot add device info to SystemInfo");
-                break;
-            }
-            useAngle = (ANGLEShouldBeUsedForApplication)(rulesHandle, rulesVersion,
-                                                         systemInfoHandle, mAngleAppName.c_str());
-            (ANGLEFreeRulesHandle)(rulesHandle);
-            (ANGLEFreeSystemInfoHandle)(systemInfoHandle);
-        } break;
-
-        default:
-            ALOGW("Version %u of ANGLE feature-support library is NOT supported.", versionToUse);
-    }
-
-    ALOGV("Close temporarily-loaded ANGLE opt-in/out logic");
-    return useAngle;
-}
-
 bool GraphicsEnv::shouldUseAngle(std::string appName) {
     if (appName != mAngleAppName) {
         // Make sure we are checking the app we were init'ed for
@@ -444,31 +370,20 @@
     const char* ANGLE_PREFER_ANGLE = "angle";
     const char* ANGLE_PREFER_NATIVE = "native";
 
+    mUseAngle = NO;
     if (mAngleDeveloperOptIn == ANGLE_PREFER_ANGLE) {
         ALOGV("User set \"Developer Options\" to force the use of ANGLE");
         mUseAngle = YES;
     } else if (mAngleDeveloperOptIn == ANGLE_PREFER_NATIVE) {
         ALOGV("User set \"Developer Options\" to force the use of Native");
-        mUseAngle = NO;
     } else {
-        // The "Developer Options" value wasn't set to force the use of ANGLE.  Need to temporarily
-        // load ANGLE and call the updatable opt-in/out logic:
-        void* featureSo = loadLibrary("feature_support");
-        if (featureSo) {
-            ALOGV("loaded ANGLE's opt-in/out logic from namespace");
-            mUseAngle = checkAngleRules(featureSo) ? YES : NO;
-            dlclose(featureSo);
-            featureSo = nullptr;
-        } else {
-            ALOGV("Could not load the ANGLE opt-in/out logic, cannot use ANGLE.");
-        }
+        ALOGV("User set invalid \"Developer Options\": '%s'", mAngleDeveloperOptIn.c_str());
     }
 }
 
 void GraphicsEnv::setAngleInfo(const std::string path, const std::string appName,
                                const std::string developerOptIn,
-                               const std::vector<std::string> eglFeatures, const int rulesFd,
-                               const long rulesOffset, const long rulesLength) {
+                               const std::vector<std::string> eglFeatures) {
     if (mUseAngle != UNKNOWN) {
         // We've already figured out an answer for this app, so just return.
         ALOGV("Already evaluated the rules file for '%s': use ANGLE = %s", appName.c_str(),
@@ -485,22 +400,6 @@
     ALOGV("setting ANGLE application opt-in to '%s'", developerOptIn.c_str());
     mAngleDeveloperOptIn = developerOptIn;
 
-    lseek(rulesFd, rulesOffset, SEEK_SET);
-    mRulesBuffer = std::vector<char>(rulesLength + 1);
-    ssize_t numBytesRead = read(rulesFd, mRulesBuffer.data(), rulesLength);
-    if (numBytesRead < 0) {
-        ALOGE("Cannot read rules file: numBytesRead = %zd", numBytesRead);
-        numBytesRead = 0;
-    } else if (numBytesRead == 0) {
-        ALOGW("Empty rules file");
-    }
-    if (numBytesRead != rulesLength) {
-        ALOGW("Did not read all of the necessary bytes from the rules file."
-              "expected: %ld, got: %zd",
-              rulesLength, numBytesRead);
-    }
-    mRulesBuffer[numBytesRead] = '\0';
-
     // Update the current status of whether we should use ANGLE or not
     updateUseAngle();
 }
diff --git a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
index 900fc49..56d1139 100644
--- a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
+++ b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
@@ -97,8 +97,7 @@
     // in the search path must have a '!' after the zip filename, e.g.
     //     /system/app/ANGLEPrebuilt/ANGLEPrebuilt.apk!/lib/arm64-v8a
     void setAngleInfo(const std::string path, const std::string appName, std::string devOptIn,
-                      const std::vector<std::string> eglFeatures, const int rulesFd,
-                      const long rulesOffset, const long rulesLength);
+                      const std::vector<std::string> eglFeatures);
     // Get the ANGLE driver namespace.
     android_namespace_t* getAngleNamespace();
     // Get the app name for ANGLE debug message.
@@ -129,8 +128,6 @@
 
     // Load requested ANGLE library.
     void* loadLibrary(std::string name);
-    // Check ANGLE support with the rules.
-    bool checkAngleRules(void* so);
     // Update whether ANGLE should be used.
     void updateUseAngle();
     // Link updatable driver namespace with llndk and vndk-sp libs.
@@ -159,8 +156,6 @@
     std::string mAngleDeveloperOptIn;
     // ANGLE EGL features;
     std::vector<std::string> mAngleEglFeatures;
-    // ANGLE rules.
-    std::vector<char> mRulesBuffer;
     // Use ANGLE flag.
     UseAngle mUseAngle = UNKNOWN;
     // Vulkan debug layers libs.
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 2d8fff9..b0dc27f 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -94,6 +94,12 @@
     include_dirs: [
         "frameworks/native/include",
     ],
+
+    target: {
+        darwin: {
+            enabled: false,
+        },
+    },
 }
 
 filegroup {
diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 0d7795e..bab9ebf 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -123,11 +123,11 @@
         return remote()->transact(BnSurfaceComposer::CAPTURE_DISPLAY, data, &reply);
     }
 
-    status_t captureDisplay(uint64_t displayOrLayerStack,
+    status_t captureDisplay(DisplayId displayId,
                             const sp<IScreenCaptureListener>& captureListener) override {
         Parcel data, reply;
         data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
-        SAFE_PARCEL(data.writeUint64, displayOrLayerStack);
+        SAFE_PARCEL(data.writeUint64, displayId.value);
         SAFE_PARCEL(data.writeStrongBinder, IInterface::asBinder(captureListener));
 
         return remote()->transact(BnSurfaceComposer::CAPTURE_DISPLAY_BY_ID, data, &reply);
@@ -281,9 +281,14 @@
             NO_ERROR) {
             std::vector<uint64_t> rawIds;
             if (reply.readUint64Vector(&rawIds) == NO_ERROR) {
-                std::vector<PhysicalDisplayId> displayIds(rawIds.size());
-                std::transform(rawIds.begin(), rawIds.end(), displayIds.begin(),
-                               [](uint64_t rawId) { return PhysicalDisplayId(rawId); });
+                std::vector<PhysicalDisplayId> displayIds;
+                displayIds.reserve(rawIds.size());
+
+                for (const uint64_t rawId : rawIds) {
+                    if (const auto id = DisplayId::fromValue<PhysicalDisplayId>(rawId)) {
+                        displayIds.push_back(*id);
+                    }
+                }
                 return displayIds;
             }
         }
@@ -1327,12 +1332,15 @@
         }
         case CAPTURE_DISPLAY_BY_ID: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
-            uint64_t displayOrLayerStack = 0;
+            uint64_t value;
+            SAFE_PARCEL(data.readUint64, &value);
+            const auto id = DisplayId::fromValue(value);
+            if (!id) return BAD_VALUE;
+
             sp<IScreenCaptureListener> captureListener;
-            SAFE_PARCEL(data.readUint64, &displayOrLayerStack);
             SAFE_PARCEL(data.readStrongBinder, &captureListener);
 
-            return captureDisplay(displayOrLayerStack, captureListener);
+            return captureDisplay(*id, captureListener);
         }
         case CAPTURE_LAYERS: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
@@ -1399,9 +1407,9 @@
         }
         case GET_PHYSICAL_DISPLAY_TOKEN: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
-            PhysicalDisplayId displayId(data.readUint64());
-            sp<IBinder> display = getPhysicalDisplayToken(displayId);
-            reply->writeStrongBinder(display);
+            const auto id = DisplayId::fromValue<PhysicalDisplayId>(data.readUint64());
+            if (!id) return BAD_VALUE;
+            reply->writeStrongBinder(getPhysicalDisplayToken(*id));
             return NO_ERROR;
         }
         case GET_DISPLAY_STATE: {
diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index c52c644..ec03c21 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -2152,12 +2152,12 @@
     return s->captureDisplay(captureArgs, captureListener);
 }
 
-status_t ScreenshotClient::captureDisplay(uint64_t displayOrLayerStack,
+status_t ScreenshotClient::captureDisplay(DisplayId displayId,
                                           const sp<IScreenCaptureListener>& captureListener) {
     sp<ISurfaceComposer> s(ComposerService::getComposerService());
     if (s == nullptr) return NO_INIT;
 
-    return s->captureDisplay(displayOrLayerStack, captureListener);
+    return s->captureDisplay(displayId, captureListener);
 }
 
 status_t ScreenshotClient::captureLayers(const LayerCaptureArgs& captureArgs,
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index 71b80d3..c0a2335 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -115,6 +115,11 @@
 
     using EventRegistrationFlags = Flags<EventRegistration>;
 
+    template <typename T>
+    struct SpHash {
+        size_t operator()(const sp<T>& k) const { return std::hash<T*>()(k.get()); }
+    };
+
     /*
      * Create a connection with SurfaceFlinger.
      */
@@ -238,24 +243,17 @@
      * The subregion can be optionally rotated.  It will also be scaled to
      * match the size of the output buffer.
      */
-    virtual status_t captureDisplay(const DisplayCaptureArgs& args,
-                                    const sp<IScreenCaptureListener>& captureListener) = 0;
+    virtual status_t captureDisplay(const DisplayCaptureArgs&,
+                                    const sp<IScreenCaptureListener>&) = 0;
 
-    virtual status_t captureDisplay(uint64_t displayOrLayerStack,
-                                    const sp<IScreenCaptureListener>& captureListener) = 0;
-
-    template <class AA>
-    struct SpHash {
-        size_t operator()(const sp<AA>& k) const { return std::hash<AA*>()(k.get()); }
-    };
+    virtual status_t captureDisplay(DisplayId, const sp<IScreenCaptureListener>&) = 0;
 
     /**
      * Capture a subtree of the layer hierarchy, potentially ignoring the root node.
      * This requires READ_FRAME_BUFFER permission. This function will fail if there
      * is a secure window on screen
      */
-    virtual status_t captureLayers(const LayerCaptureArgs& args,
-                                   const sp<IScreenCaptureListener>& captureListener) = 0;
+    virtual status_t captureLayers(const LayerCaptureArgs&, const sp<IScreenCaptureListener>&) = 0;
 
     /* Clears the frame statistics for animations.
      *
diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index ff97fe4..1dfc83b 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -631,12 +631,9 @@
 
 class ScreenshotClient {
 public:
-    static status_t captureDisplay(const DisplayCaptureArgs& captureArgs,
-                                   const sp<IScreenCaptureListener>& captureListener);
-    static status_t captureDisplay(uint64_t displayOrLayerStack,
-                                   const sp<IScreenCaptureListener>& captureListener);
-    static status_t captureLayers(const LayerCaptureArgs& captureArgs,
-                                  const sp<IScreenCaptureListener>& captureListener);
+    static status_t captureDisplay(const DisplayCaptureArgs&, const sp<IScreenCaptureListener>&);
+    static status_t captureDisplay(DisplayId, const sp<IScreenCaptureListener>&);
+    static status_t captureLayers(const LayerCaptureArgs&, const sp<IScreenCaptureListener>&);
 };
 
 // ---------------------------------------------------------------------------
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 59b0c04..8d7a356 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -752,21 +752,19 @@
     }
     status_t setActiveColorMode(const sp<IBinder>& /*display*/,
         ColorMode /*colorMode*/) override { return NO_ERROR; }
-    status_t captureDisplay(const DisplayCaptureArgs& /* captureArgs */,
-                            const sp<IScreenCaptureListener>& /* captureListener */) override {
-        return NO_ERROR;
-    }
     void setAutoLowLatencyMode(const sp<IBinder>& /*display*/, bool /*on*/) override {}
     void setGameContentType(const sp<IBinder>& /*display*/, bool /*on*/) override {}
-    status_t captureDisplay(uint64_t /*displayOrLayerStack*/,
-                            const sp<IScreenCaptureListener>& /* captureListener */) override {
+
+    status_t captureDisplay(const DisplayCaptureArgs&, const sp<IScreenCaptureListener>&) override {
         return NO_ERROR;
     }
-    virtual status_t captureLayers(
-            const LayerCaptureArgs& /* captureArgs */,
-            const sp<IScreenCaptureListener>& /* captureListener */) override {
+    status_t captureDisplay(DisplayId, const sp<IScreenCaptureListener>&) override {
         return NO_ERROR;
     }
+    status_t captureLayers(const LayerCaptureArgs&, const sp<IScreenCaptureListener>&) override {
+        return NO_ERROR;
+    }
+
     status_t clearAnimationFrameStats() override { return NO_ERROR; }
     status_t getAnimationFrameStats(FrameStats* /*outStats*/) const override {
         return NO_ERROR;
diff --git a/libs/input/Input.cpp b/libs/input/Input.cpp
index 2860aa3..82a814f 100644
--- a/libs/input/Input.cpp
+++ b/libs/input/Input.cpp
@@ -320,10 +320,6 @@
     scaleAxisValue(*this, AMOTION_EVENT_AXIS_RELATIVE_Y, windowYScale);
 }
 
-void PointerCoords::scale(float globalScaleFactor) {
-    scale(globalScaleFactor, globalScaleFactor, globalScaleFactor);
-}
-
 void PointerCoords::applyOffset(float xOffset, float yOffset) {
     setAxisValue(AMOTION_EVENT_AXIS_X, getX() + xOffset);
     setAxisValue(AMOTION_EVENT_AXIS_Y, getY() + yOffset);
diff --git a/libs/nativedisplay/AChoreographer.cpp b/libs/nativedisplay/AChoreographer.cpp
index 2dd6c4f..6a14d4f 100644
--- a/libs/nativedisplay/AChoreographer.cpp
+++ b/libs/nativedisplay/AChoreographer.cpp
@@ -305,8 +305,9 @@
         // Fortunately, these events are small so sending packets across the
         // socket should be atomic across processes.
         DisplayEventReceiver::Event event;
-        event.header = DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
-                                                           PhysicalDisplayId(0), systemTime()};
+        event.header =
+                DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
+                                                    PhysicalDisplayId::fromPort(0), systemTime()};
         injectEvent(event);
     }
 }
diff --git a/libs/nativewindow/include/android/hardware_buffer.h b/libs/nativewindow/include/android/hardware_buffer.h
index d93a84c..d5e7cb2 100644
--- a/libs/nativewindow/include/android/hardware_buffer.h
+++ b/libs/nativewindow/include/android/hardware_buffer.h
@@ -556,6 +556,7 @@
                                    int32_t* _Nonnull outBytesPerPixel,
                                    int32_t* _Nonnull outBytesPerStride) __INTRODUCED_IN(29);
 
+
 /**
  * Get the system wide unique id for an AHardwareBuffer.
  *
diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index 467f848..b1e1014 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -1156,10 +1156,6 @@
 
     const mat4 projectionMatrix =
             ui::Transform(display.orientation).asMatrix4() * mState.projectionMatrix;
-    if (!display.clearRegion.isEmpty()) {
-        glDisable(GL_BLEND);
-        fillRegionWithColor(display.clearRegion, 0.0, 0.0, 0.0, 1.0);
-    }
 
     Mesh mesh = Mesh::Builder()
                         .setPrimitive(Mesh::TRIANGLE_FAN)
diff --git a/libs/renderengine/include/renderengine/DisplaySettings.h b/libs/renderengine/include/renderengine/DisplaySettings.h
index 53fa622..d395d06 100644
--- a/libs/renderengine/include/renderengine/DisplaySettings.h
+++ b/libs/renderengine/include/renderengine/DisplaySettings.h
@@ -51,10 +51,6 @@
     // dataspace, in non-linear space.
     mat4 colorTransform = mat4();
 
-    // Region that will be cleared to (0, 0, 0, 1) prior to rendering.
-    // This is specified in layer-stack space.
-    Region clearRegion = Region::INVALID_REGION;
-
     // An additional orientation flag to be applied after clipping the output.
     // By way of example, this may be used for supporting fullscreen screenshot
     // capture of a device in landscape while the buffer is in portrait
@@ -68,8 +64,7 @@
 static inline bool operator==(const DisplaySettings& lhs, const DisplaySettings& rhs) {
     return lhs.physicalDisplay == rhs.physicalDisplay && lhs.clip == rhs.clip &&
             lhs.maxLuminance == rhs.maxLuminance && lhs.outputDataspace == rhs.outputDataspace &&
-            lhs.colorTransform == rhs.colorTransform &&
-            lhs.clearRegion.hasSameRects(rhs.clearRegion) && lhs.orientation == rhs.orientation;
+            lhs.colorTransform == rhs.colorTransform && lhs.orientation == rhs.orientation;
 }
 
 // Defining PrintTo helps with Google Tests.
@@ -84,9 +79,6 @@
     PrintTo(settings.outputDataspace, os);
     *os << "\n    .colorTransform = " << settings.colorTransform;
     *os << "\n    .clearRegion = ";
-    PrintTo(settings.clearRegion, os);
-    *os << "\n    .orientation = " << settings.orientation;
-    *os << "\n}";
 }
 
 } // namespace renderengine
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index f4b07d0..16b5884 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -812,28 +812,6 @@
     canvas->clear(SK_ColorTRANSPARENT);
     initCanvas(canvas, display);
 
-    // TODO: clearRegion was required for SurfaceView when a buffer is not yet available but the
-    // view is still on-screen. The clear region could be re-specified as a black color layer,
-    // however.
-    if (!display.clearRegion.isEmpty()) {
-        ATRACE_NAME("ClearRegion");
-        size_t numRects = 0;
-        Rect const* rects = display.clearRegion.getArray(&numRects);
-        SkIRect skRects[numRects];
-        for (int i = 0; i < numRects; ++i) {
-            skRects[i] =
-                    SkIRect::MakeLTRB(rects[i].left, rects[i].top, rects[i].right, rects[i].bottom);
-        }
-        SkRegion clearRegion;
-        SkPaint paint;
-        sk_sp<SkShader> shader =
-                SkShaders::Color(SkColor4f{.fR = 0., .fG = 0., .fB = 0., .fA = 1.0},
-                                 toSkColorSpace(dstDataspace));
-        paint.setShader(shader);
-        clearRegion.setRects(skRects, numRects);
-        canvas->drawRegion(clearRegion, paint);
-    }
-
     for (const auto& layer : layers) {
         ATRACE_FORMAT("DrawLayer: %s", layer->name.c_str());
 
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index 33e3773..ec47f96 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -524,10 +524,6 @@
 
     void fillGreenColorBufferThenClearRegion();
 
-    void clearLeftRegion();
-
-    void clearRegion();
-
     template <typename SourceVariant>
     void drawShadow(const renderengine::LayerSettings& castingLayer,
                     const renderengine::ShadowSettings& shadow, const ubyte4& casterColor,
@@ -1195,28 +1191,6 @@
     expectBufferColor(fullscreenRect(), 128, 0, 0, 128, 1);
 }
 
-void RenderEngineTest::clearLeftRegion() {
-    renderengine::DisplaySettings settings;
-    settings.physicalDisplay = fullscreenRect();
-    // Here logical space is 4x4
-    settings.clip = Rect(4, 4);
-    settings.clearRegion = Region(Rect(2, 4));
-    std::vector<const renderengine::LayerSettings*> layers;
-    // fake layer, without bounds should not render anything
-    renderengine::LayerSettings layer;
-    layers.push_back(&layer);
-    invokeDraw(settings, layers);
-}
-
-void RenderEngineTest::clearRegion() {
-    // Reuse mBuffer
-    clearLeftRegion();
-    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT), 0, 0, 0, 255);
-    expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 2, 0, DEFAULT_DISPLAY_WIDTH,
-                           DEFAULT_DISPLAY_HEIGHT),
-                      0, 0, 0, 0);
-}
-
 template <typename SourceVariant>
 void RenderEngineTest::drawShadow(const renderengine::LayerSettings& castingLayer,
                                   const renderengine::ShadowSettings& shadow,
@@ -1647,11 +1621,6 @@
     fillBufferWithoutPremultiplyAlpha();
 }
 
-TEST_P(RenderEngineTest, drawLayers_clearRegion) {
-    initializeRenderEngine();
-    clearRegion();
-}
-
 TEST_P(RenderEngineTest, drawLayers_fillShadow_castsWithoutCasterLayer) {
     initializeRenderEngine();
 
diff --git a/libs/ui/Android.bp b/libs/ui/Android.bp
index 74d17ce..5a118ec 100644
--- a/libs/ui/Android.bp
+++ b/libs/ui/Android.bp
@@ -137,7 +137,6 @@
         "HdrCapabilities.cpp",
         "PixelFormat.cpp",
         "PublicFormat.cpp",
-        "Size.cpp",
         "StaticDisplayInfo.cpp",
     ],
 
diff --git a/libs/ui/Size.cpp b/libs/ui/Size.cpp
deleted file mode 100644
index d2996d1..0000000
--- a/libs/ui/Size.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <ui/Size.h>
-
-namespace android::ui {
-
-const Size Size::INVALID{-1, -1};
-const Size Size::EMPTY{0, 0};
-
-} // namespace android::ui
diff --git a/libs/ui/include/ui/DisplayId.h b/libs/ui/include/ui/DisplayId.h
index f196ab9..9120972 100644
--- a/libs/ui/include/ui/DisplayId.h
+++ b/libs/ui/include/ui/DisplayId.h
@@ -38,12 +38,22 @@
 
     uint64_t value;
 
+    // For deserialization.
+    static constexpr std::optional<DisplayId> fromValue(uint64_t);
+
+    // As above, but also upcast to Id.
+    template <typename Id>
+    static constexpr std::optional<Id> fromValue(uint64_t value) {
+        if (const auto id = Id::tryCast(DisplayId(value))) {
+            return id;
+        }
+        return {};
+    }
+
 protected:
     explicit constexpr DisplayId(uint64_t id) : value(id) {}
 };
 
-static_assert(sizeof(DisplayId) == sizeof(uint64_t));
-
 inline bool operator==(DisplayId lhs, DisplayId rhs) {
     return lhs.value == rhs.value;
 }
@@ -80,11 +90,8 @@
 
     // TODO(b/162612135) Remove default constructor
     PhysicalDisplayId() = default;
-    // TODO(b/162612135) Remove constructor
-    explicit constexpr PhysicalDisplayId(uint64_t id) : DisplayId(id) {}
 
     constexpr uint16_t getManufacturerId() const { return static_cast<uint16_t>(value >> 40); }
-
     constexpr uint8_t getPort() const { return static_cast<uint8_t>(value); }
 
 private:
@@ -96,10 +103,9 @@
     explicit constexpr PhysicalDisplayId(DisplayId other) : DisplayId(other) {}
 };
 
-static_assert(sizeof(PhysicalDisplayId) == sizeof(uint64_t));
-
 struct VirtualDisplayId : DisplayId {
     using BaseId = uint32_t;
+
     // Flag indicating that this virtual display is backed by the GPU.
     static constexpr uint64_t FLAG_GPU = 1ULL << 61;
 
@@ -163,10 +169,23 @@
     explicit constexpr HalDisplayId(DisplayId other) : DisplayId(other) {}
 };
 
+constexpr std::optional<DisplayId> DisplayId::fromValue(uint64_t value) {
+    if (const auto id = fromValue<PhysicalDisplayId>(value)) {
+        return id;
+    }
+    if (const auto id = fromValue<VirtualDisplayId>(value)) {
+        return id;
+    }
+    return {};
+}
+
+static_assert(sizeof(DisplayId) == sizeof(uint64_t));
+static_assert(sizeof(HalDisplayId) == sizeof(uint64_t));
 static_assert(sizeof(VirtualDisplayId) == sizeof(uint64_t));
+
+static_assert(sizeof(PhysicalDisplayId) == sizeof(uint64_t));
 static_assert(sizeof(HalVirtualDisplayId) == sizeof(uint64_t));
 static_assert(sizeof(GpuVirtualDisplayId) == sizeof(uint64_t));
-static_assert(sizeof(HalDisplayId) == sizeof(uint64_t));
 
 } // namespace android
 
diff --git a/libs/ui/include/ui/Size.h b/libs/ui/include/ui/Size.h
index f1e8252..ecc192d 100644
--- a/libs/ui/include/ui/Size.h
+++ b/libs/ui/include/ui/Size.h
@@ -23,103 +23,70 @@
 #include <type_traits>
 #include <utility>
 
-namespace android {
-namespace ui {
+namespace android::ui {
 
-// Forward declare a few things.
-struct Size;
-bool operator==(const Size& lhs, const Size& rhs);
-
-/**
- * A simple value type representing a two-dimensional size
- */
+// A simple value type representing a two-dimensional size.
 struct Size {
-    int32_t width;
-    int32_t height;
+    int32_t width = -1;
+    int32_t height = -1;
 
-    // Special values
-    static const Size INVALID;
-    static const Size EMPTY;
+    constexpr Size() = default;
 
-    // ------------------------------------------------------------------------
-    // Construction
-    // ------------------------------------------------------------------------
-
-    Size() : Size(INVALID) {}
     template <typename T>
-    Size(T&& w, T&& h)
-          : width(Size::clamp<int32_t, T>(std::forward<T>(w))),
-            height(Size::clamp<int32_t, T>(std::forward<T>(h))) {}
-
-    // ------------------------------------------------------------------------
-    // Accessors
-    // ------------------------------------------------------------------------
+    constexpr Size(T w, T h) : width(clamp<int32_t>(w)), height(clamp<int32_t>(h)) {}
 
     int32_t getWidth() const { return width; }
     int32_t getHeight() const { return height; }
 
-    template <typename T>
-    void setWidth(T&& v) {
-        width = Size::clamp<int32_t, T>(std::forward<T>(v));
-    }
-    template <typename T>
-    void setHeight(T&& v) {
-        height = Size::clamp<int32_t, T>(std::forward<T>(v));
-    }
-
-    // ------------------------------------------------------------------------
-    // Assignment
-    // ------------------------------------------------------------------------
-
-    void set(const Size& size) { *this = size; }
-    template <typename T>
-    void set(T&& w, T&& h) {
-        set(Size(std::forward<T>(w), std::forward<T>(h)));
-    }
-
-    // Sets the value to INVALID
-    void makeInvalid() { set(INVALID); }
-
-    // Sets the value to EMPTY
-    void clear() { set(EMPTY); }
-
-    // ------------------------------------------------------------------------
-    // Semantic checks
-    // ------------------------------------------------------------------------
-
     // Valid means non-negative width and height
     bool isValid() const { return width >= 0 && height >= 0; }
 
     // Empty means zero width and height
-    bool isEmpty() const { return *this == EMPTY; }
+    bool isEmpty() const;
 
-    // ------------------------------------------------------------------------
-    // Clamp Helpers
-    // ------------------------------------------------------------------------
-
-    // Note: We use only features available in C++11 here for compatibility with
-    // external targets which include this file directly or indirectly and which
-    // themselves use C++11.
-
-    // C++11 compatible replacement for std::remove_cv_reference_t [C++20]
     template <typename T>
-    using remove_cv_reference_t =
-            typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+    void setWidth(T v) {
+        width = clamp<int32_t>(v);
+    }
+
+    template <typename T>
+    void setHeight(T v) {
+        height = clamp<int32_t>(v);
+    }
+
+    void set(Size size) { *this = size; }
+
+    template <typename T>
+    void set(T w, T h) {
+        set(Size(w, h));
+    }
+
+    // Sets the value to kInvalidSize
+    void makeInvalid();
+
+    // Sets the value to kEmptySize
+    void clear();
+
+    // TODO: Replace with std::remove_cvref_t in C++20.
+    template <typename T>
+    using remove_cvref_t = std::remove_cv_t<std::remove_reference_t<T>>;
 
     // Takes a value of type FromType, and ensures it can be represented as a value of type ToType,
     // clamping the input value to the output range if necessary.
     template <typename ToType, typename FromType>
-    static Size::remove_cv_reference_t<ToType>
-    clamp(typename std::enable_if<
-            std::numeric_limits<Size::remove_cv_reference_t<ToType>>::is_specialized &&
-                    std::numeric_limits<Size::remove_cv_reference_t<FromType>>::is_specialized,
-            FromType>::type v) {
-        using BareToType = remove_cv_reference_t<ToType>;
-        using BareFromType = remove_cv_reference_t<FromType>;
-        static constexpr auto toHighest = std::numeric_limits<BareToType>::max();
-        static constexpr auto toLowest = std::numeric_limits<BareToType>::lowest();
-        static constexpr auto fromHighest = std::numeric_limits<BareFromType>::max();
-        static constexpr auto fromLowest = std::numeric_limits<BareFromType>::lowest();
+    static constexpr remove_cvref_t<ToType> clamp(FromType v) {
+        using BareToType = remove_cvref_t<ToType>;
+        using ToLimits = std::numeric_limits<BareToType>;
+
+        using BareFromType = remove_cvref_t<FromType>;
+        using FromLimits = std::numeric_limits<BareFromType>;
+
+        static_assert(ToLimits::is_specialized && FromLimits::is_specialized);
+
+        constexpr auto toHighest = ToLimits::max();
+        constexpr auto toLowest = ToLimits::lowest();
+        constexpr auto fromHighest = FromLimits::max();
+        constexpr auto fromLowest = FromLimits::lowest();
 
         // Get the closest representation of [toLowest, toHighest] in type
         // FromType to use to clamp the input value before conversion.
@@ -127,37 +94,35 @@
         // std::common_type<...> is used to get a value-preserving type for the
         // top end of the range.
         using CommonHighestType = std::common_type_t<BareToType, BareFromType>;
+        using CommonLimits = std::numeric_limits<CommonHighestType>;
 
         // std::make_signed<std::common_type<...>> is used to get a
         // value-preserving type for the bottom end of the range, except this is
         // a bit trickier for non-integer types like float.
-        using CommonLowestType =
-                std::conditional_t<std::numeric_limits<CommonHighestType>::is_integer,
-                                   std::make_signed_t<std::conditional_t<
-                                           std::numeric_limits<CommonHighestType>::is_integer,
-                                           CommonHighestType, int /* not used */>>,
-                                   CommonHighestType>;
+        using CommonLowestType = std::conditional_t<
+                CommonLimits::is_integer,
+                std::make_signed_t<std::conditional_t<CommonLimits::is_integer, CommonHighestType,
+                                                      int /* not used */>>,
+                CommonHighestType>;
 
         // We can then compute the clamp range in a way that can be later
         // trivially converted to either the 'from' or 'to' types, and be
-        // representabile in either.
-        static constexpr auto commonClampHighest =
-                std::min(static_cast<CommonHighestType>(fromHighest),
-                         static_cast<CommonHighestType>(toHighest));
-        static constexpr auto commonClampLowest =
-                std::max(static_cast<CommonLowestType>(fromLowest),
-                         static_cast<CommonLowestType>(toLowest));
+        // representable in either.
+        constexpr auto commonClampHighest = std::min(static_cast<CommonHighestType>(fromHighest),
+                                                     static_cast<CommonHighestType>(toHighest));
+        constexpr auto commonClampLowest = std::max(static_cast<CommonLowestType>(fromLowest),
+                                                    static_cast<CommonLowestType>(toLowest));
 
-        static constexpr auto fromClampHighest = static_cast<BareFromType>(commonClampHighest);
-        static constexpr auto fromClampLowest = static_cast<BareFromType>(commonClampLowest);
+        constexpr auto fromClampHighest = static_cast<BareFromType>(commonClampHighest);
+        constexpr auto fromClampLowest = static_cast<BareFromType>(commonClampLowest);
 
         // A clamp is needed only if the range we are clamping to is not the
         // same as the range of the input.
-        static constexpr bool isClampNeeded =
+        constexpr bool isClampNeeded =
                 (fromLowest != fromClampLowest) || (fromHighest != fromClampHighest);
 
         // If a clamp is not needed, the conversion is just a trivial cast.
-        if (!isClampNeeded) {
+        if constexpr (!isClampNeeded) {
             return static_cast<BareToType>(v);
         }
 
@@ -170,34 +135,46 @@
 
         // Otherwise clamping is done by using the already computed endpoints
         // for each type.
-        return (v <= fromClampLowest)
-                ? toClampLowest
-                : ((v >= fromClampHighest) ? toClampHighest : static_cast<BareToType>(v));
+        if (v <= fromClampLowest) {
+            return toClampLowest;
+        }
+
+        return v >= fromClampHighest ? toClampHighest : static_cast<BareToType>(v);
     }
 };
 
-// ------------------------------------------------------------------------
-// Comparisons
-// ------------------------------------------------------------------------
+constexpr Size kInvalidSize;
+constexpr Size kEmptySize{0, 0};
 
-inline bool operator==(const Size& lhs, const Size& rhs) {
+inline void Size::makeInvalid() {
+    set(kInvalidSize);
+}
+
+inline void Size::clear() {
+    set(kEmptySize);
+}
+
+inline bool operator==(Size lhs, Size rhs) {
     return lhs.width == rhs.width && lhs.height == rhs.height;
 }
 
-inline bool operator!=(const Size& lhs, const Size& rhs) {
-    return !operator==(lhs, rhs);
+inline bool Size::isEmpty() const {
+    return *this == kEmptySize;
 }
 
-inline bool operator<(const Size& lhs, const Size& rhs) {
+inline bool operator!=(Size lhs, Size rhs) {
+    return !(lhs == rhs);
+}
+
+inline bool operator<(Size lhs, Size rhs) {
     // Orders by increasing width, then height.
     if (lhs.width != rhs.width) return lhs.width < rhs.width;
     return lhs.height < rhs.height;
 }
 
 // Defining PrintTo helps with Google Tests.
-static inline void PrintTo(const Size& size, ::std::ostream* os) {
-    *os << "Size(" << size.width << ", " << size.height << ")";
+inline void PrintTo(Size size, std::ostream* stream) {
+    *stream << "Size(" << size.width << ", " << size.height << ')';
 }
 
-} // namespace ui
-} // namespace android
+} // namespace android::ui
diff --git a/libs/ui/tests/DisplayId_test.cpp b/libs/ui/tests/DisplayId_test.cpp
index 1d908b8..8ddee7e 100644
--- a/libs/ui/tests/DisplayId_test.cpp
+++ b/libs/ui/tests/DisplayId_test.cpp
@@ -32,6 +32,9 @@
     EXPECT_FALSE(GpuVirtualDisplayId::tryCast(id));
     EXPECT_TRUE(PhysicalDisplayId::tryCast(id));
     EXPECT_TRUE(HalDisplayId::tryCast(id));
+
+    EXPECT_EQ(id, DisplayId::fromValue(id.value));
+    EXPECT_EQ(id, DisplayId::fromValue<PhysicalDisplayId>(id.value));
 }
 
 TEST(DisplayIdTest, createPhysicalIdFromPort) {
@@ -43,6 +46,9 @@
     EXPECT_FALSE(GpuVirtualDisplayId::tryCast(id));
     EXPECT_TRUE(PhysicalDisplayId::tryCast(id));
     EXPECT_TRUE(HalDisplayId::tryCast(id));
+
+    EXPECT_EQ(id, DisplayId::fromValue(id.value));
+    EXPECT_EQ(id, DisplayId::fromValue<PhysicalDisplayId>(id.value));
 }
 
 TEST(DisplayIdTest, createGpuVirtualId) {
@@ -52,6 +58,9 @@
     EXPECT_FALSE(HalVirtualDisplayId::tryCast(id));
     EXPECT_FALSE(PhysicalDisplayId::tryCast(id));
     EXPECT_FALSE(HalDisplayId::tryCast(id));
+
+    EXPECT_EQ(id, DisplayId::fromValue(id.value));
+    EXPECT_EQ(id, DisplayId::fromValue<GpuVirtualDisplayId>(id.value));
 }
 
 TEST(DisplayIdTest, createHalVirtualId) {
@@ -61,6 +70,9 @@
     EXPECT_FALSE(GpuVirtualDisplayId::tryCast(id));
     EXPECT_FALSE(PhysicalDisplayId::tryCast(id));
     EXPECT_TRUE(HalDisplayId::tryCast(id));
+
+    EXPECT_EQ(id, DisplayId::fromValue(id.value));
+    EXPECT_EQ(id, DisplayId::fromValue<HalVirtualDisplayId>(id.value));
 }
 
 } // namespace android::ui
diff --git a/libs/ui/tests/Size_test.cpp b/libs/ui/tests/Size_test.cpp
index 5f75aea..acef47f 100644
--- a/libs/ui/tests/Size_test.cpp
+++ b/libs/ui/tests/Size_test.cpp
@@ -93,9 +93,8 @@
     }
 
     {
-        const auto& s = Size::INVALID;
-        EXPECT_FALSE(s.isValid());
-        EXPECT_FALSE(s.isEmpty());
+        EXPECT_FALSE(kInvalidSize.isValid());
+        EXPECT_FALSE(kInvalidSize.isEmpty());
     }
 
     {
@@ -112,9 +111,8 @@
     }
 
     {
-        const auto& s = Size::EMPTY;
-        EXPECT_TRUE(s.isValid());
-        EXPECT_TRUE(s.isEmpty());
+        EXPECT_TRUE(kEmptySize.isValid());
+        EXPECT_TRUE(kEmptySize.isEmpty());
     }
 
     {
diff --git a/services/automotive/display/AutomotiveDisplayProxyService.cpp b/services/automotive/display/AutomotiveDisplayProxyService.cpp
index d6fc695..d205231 100644
--- a/services/automotive/display/AutomotiveDisplayProxyService.cpp
+++ b/services/automotive/display/AutomotiveDisplayProxyService.cpp
@@ -34,7 +34,10 @@
     sp<IBinder> displayToken = nullptr;
     sp<SurfaceControl> surfaceControl = nullptr;
     if (it == mDisplays.end()) {
-        displayToken = SurfaceComposerClient::getPhysicalDisplayToken(PhysicalDisplayId(id));
+        if (const auto displayId = DisplayId::fromValue<PhysicalDisplayId>(id)) {
+            displayToken = SurfaceComposerClient::getPhysicalDisplayToken(*displayId);
+        }
+
         if (displayToken == nullptr) {
             ALOGE("Given display id, 0x%lX, is invalid.", (unsigned long)id);
             return nullptr;
@@ -157,7 +160,11 @@
     HwDisplayConfig activeConfig;
     HwDisplayState  activeState;
 
-    auto displayToken = SurfaceComposerClient::getPhysicalDisplayToken(PhysicalDisplayId(id));
+    sp<IBinder> displayToken;
+    if (const auto displayId = DisplayId::fromValue<PhysicalDisplayId>(id)) {
+        displayToken = SurfaceComposerClient::getPhysicalDisplayToken(*displayId);
+    }
+
     if (displayToken == nullptr) {
         ALOGE("Given display id, 0x%lX, is invalid.", (unsigned long)id);
     } else {
diff --git a/services/inputflinger/dispatcher/Entry.cpp b/services/inputflinger/dispatcher/Entry.cpp
index b5ed064..8f4527d 100644
--- a/services/inputflinger/dispatcher/Entry.cpp
+++ b/services/inputflinger/dispatcher/Entry.cpp
@@ -176,10 +176,11 @@
     }
     return StringPrintf("KeyEvent(deviceId=%d, eventTime=%" PRIu64
                         ", source=0x%08x, displayId=%" PRId32 ", action=%s, "
-                        "flags=0x%08x, keyCode=%d, scanCode=%d, metaState=0x%08x, "
+                        "flags=0x%08x, keyCode=%s(%d), scanCode=%d, metaState=0x%08x, "
                         "repeatCount=%d), policyFlags=0x%08x",
                         deviceId, eventTime, source, displayId, KeyEvent::actionToString(action),
-                        flags, keyCode, scanCode, metaState, repeatCount, policyFlags);
+                        flags, KeyEvent::getLabel(keyCode), keyCode, scanCode, metaState,
+                        repeatCount, policyFlags);
 }
 
 void KeyEntry::recycle() {
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index 2988d99..07b4f30 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -906,8 +906,7 @@
         }
 
         // Alternatively, maybe there's a gesture monitor that could handle this event
-        std::vector<TouchedMonitor> gestureMonitors =
-                findTouchedGestureMonitorsLocked(displayId, {});
+        std::vector<TouchedMonitor> gestureMonitors = findTouchedGestureMonitorsLocked(displayId);
         for (TouchedMonitor& gestureMonitor : gestureMonitors) {
             sp<Connection> connection =
                     getConnectionLocked(gestureMonitor.monitor.inputChannel->getConnectionToken());
@@ -1001,11 +1000,9 @@
 sp<WindowInfoHandle> InputDispatcher::findTouchedWindowAtLocked(int32_t displayId, int32_t x,
                                                                 int32_t y, TouchState* touchState,
                                                                 bool addOutsideTargets,
-                                                                bool addPortalWindows,
                                                                 bool ignoreDragWindow) {
-    if ((addPortalWindows || addOutsideTargets) && touchState == nullptr) {
-        LOG_ALWAYS_FATAL(
-                "Must provide a valid touch state if adding portal windows or outside targets");
+    if (addOutsideTargets && touchState == nullptr) {
+        LOG_ALWAYS_FATAL("Must provide a valid touch state if adding outside targets");
     }
     // Traverse windows from front to back to find touched window.
     const std::vector<sp<WindowInfoHandle>>& windowHandles = getWindowHandlesLocked(displayId);
@@ -1022,16 +1019,6 @@
                     bool isTouchModal = !flags.test(WindowInfo::Flag::NOT_FOCUSABLE) &&
                             !flags.test(WindowInfo::Flag::NOT_TOUCH_MODAL);
                     if (isTouchModal || windowInfo->touchableRegionContainsPoint(x, y)) {
-                        int32_t portalToDisplayId = windowInfo->portalToDisplayId;
-                        if (portalToDisplayId != ADISPLAY_ID_NONE &&
-                            portalToDisplayId != displayId) {
-                            if (addPortalWindows) {
-                                // For the monitoring channels of the display.
-                                touchState->addPortalWindow(windowHandle);
-                            }
-                            return findTouchedWindowAtLocked(portalToDisplayId, x, y, touchState,
-                                                             addOutsideTargets, addPortalWindows);
-                        }
                         // Found window.
                         return windowHandle;
                     }
@@ -1049,17 +1036,11 @@
 }
 
 std::vector<TouchedMonitor> InputDispatcher::findTouchedGestureMonitorsLocked(
-        int32_t displayId, const std::vector<sp<WindowInfoHandle>>& portalWindows) const {
+        int32_t displayId) const {
     std::vector<TouchedMonitor> touchedMonitors;
 
     std::vector<Monitor> monitors = getValueByKey(mGestureMonitorsByDisplay, displayId);
     addGestureMonitors(monitors, touchedMonitors);
-    for (const sp<WindowInfoHandle>& portalWindow : portalWindows) {
-        const WindowInfo* windowInfo = portalWindow->getInfo();
-        monitors = getValueByKey(mGestureMonitorsByDisplay, windowInfo->portalToDisplayId);
-        addGestureMonitors(monitors, touchedMonitors, -windowInfo->frameLeft,
-                           -windowInfo->frameTop);
-    }
     return touchedMonitors;
 }
 
@@ -1595,23 +1576,6 @@
     // Add monitor channels from event's or focused display.
     addGlobalMonitoringTargetsLocked(inputTargets, getTargetDisplayId(*entry));
 
-    if (isPointerEvent) {
-        std::unordered_map<int32_t, TouchState>::iterator it =
-                mTouchStatesByDisplay.find(entry->displayId);
-        if (it != mTouchStatesByDisplay.end()) {
-            const TouchState& state = it->second;
-            if (!state.portalWindows.empty()) {
-                // The event has gone through these portal windows, so we add monitoring targets of
-                // the corresponding displays as well.
-                for (size_t i = 0; i < state.portalWindows.size(); i++) {
-                    const WindowInfo* windowInfo = state.portalWindows[i]->getInfo();
-                    addGlobalMonitoringTargetsLocked(inputTargets, windowInfo->portalToDisplayId,
-                                                     -windowInfo->frameLeft, -windowInfo->frameTop);
-                }
-            }
-        }
-    }
-
     // Dispatch the motion.
     if (conflictingPointerActions) {
         CancelationOptions options(CancelationOptions::CANCEL_POINTER_EVENTS,
@@ -1999,12 +1963,11 @@
             y = int32_t(entry.pointerCoords[pointerIndex].getAxisValue(AMOTION_EVENT_AXIS_Y));
         }
         bool isDown = maskedAction == AMOTION_EVENT_ACTION_DOWN;
-        newTouchedWindowHandle =
-                findTouchedWindowAtLocked(displayId, x, y, &tempTouchState,
-                                          isDown /*addOutsideTargets*/, true /*addPortalWindows*/);
+        newTouchedWindowHandle = findTouchedWindowAtLocked(displayId, x, y, &tempTouchState,
+                                                           isDown /*addOutsideTargets*/);
 
         std::vector<TouchedMonitor> newGestureMonitors = isDown
-                ? findTouchedGestureMonitorsLocked(displayId, tempTouchState.portalWindows)
+                ? findTouchedGestureMonitorsLocked(displayId)
                 : std::vector<TouchedMonitor>{};
 
         // Figure out whether splitting will be allowed for this window.
@@ -2375,8 +2338,7 @@
 void InputDispatcher::finishDragAndDrop(int32_t displayId, float x, float y) {
     const sp<WindowInfoHandle> dropWindow =
             findTouchedWindowAtLocked(displayId, x, y, nullptr /*touchState*/,
-                                      false /*addOutsideTargets*/, false /*addPortalWindows*/,
-                                      true /*ignoreDragWindow*/);
+                                      false /*addOutsideTargets*/, true /*ignoreDragWindow*/);
     if (dropWindow) {
         vec2 local = dropWindow->getInfo()->transform.transform(x, y);
         notifyDropWindowLocked(dropWindow->getToken(), local.x, local.y);
@@ -2410,8 +2372,7 @@
 
         const sp<WindowInfoHandle> hoverWindowHandle =
                 findTouchedWindowAtLocked(entry.displayId, x, y, nullptr /*touchState*/,
-                                          false /*addOutsideTargets*/, false /*addPortalWindows*/,
-                                          true /*ignoreDragWindow*/);
+                                          false /*addOutsideTargets*/, true /*ignoreDragWindow*/);
         // enqueue drag exit if needed.
         if (hoverWindowHandle != mDragState->dragHoverWindowHandle &&
             !haveSameToken(hoverWindowHandle, mDragState->dragHoverWindowHandle)) {
@@ -3907,6 +3868,13 @@
                                               args->downTime, args->pointerCount,
                                               args->pointerProperties, args->pointerCoords, 0, 0);
 
+        if (args->id != android::os::IInputConstants::INVALID_INPUT_EVENT_ID &&
+            IdGenerator::getSource(args->id) == IdGenerator::Source::INPUT_READER &&
+            !mInputFilterEnabled) {
+            const bool isDown = args->action == AMOTION_EVENT_ACTION_DOWN;
+            mLatencyTracker.trackListener(args->id, isDown, args->eventTime, args->readTime);
+        }
+
         needWake = enqueueInboundEventLocked(std::move(newEntry));
         mLock.unlock();
     } // release lock
@@ -4447,8 +4415,7 @@
         }
 
         const WindowInfo* info = handle->getInfo();
-        if ((getInputChannelLocked(handle->getToken()) == nullptr &&
-             info->portalToDisplayId == ADISPLAY_ID_NONE)) {
+        if (getInputChannelLocked(handle->getToken()) == nullptr) {
             const bool noInputChannel =
                     info->inputFeatures.test(WindowInfo::Feature::NO_INPUT_CHANNEL);
             const bool canReceiveInput = !info->flags.test(WindowInfo::Flag::NOT_TOUCHABLE) ||
@@ -5000,14 +4967,6 @@
             } else {
                 dump += INDENT3 "Windows: <none>\n";
             }
-            if (!state.portalWindows.empty()) {
-                dump += INDENT3 "Portal windows:\n";
-                for (size_t i = 0; i < state.portalWindows.size(); i++) {
-                    const sp<WindowInfoHandle> portalWindowHandle = state.portalWindows[i];
-                    dump += StringPrintf(INDENT4 "%zu: name='%s'\n", i,
-                                         portalWindowHandle->getName().c_str());
-                }
-            }
         }
     } else {
         dump += INDENT "TouchStates: <no displays touched>\n";
@@ -5029,7 +4988,7 @@
                     const WindowInfo* windowInfo = windowHandle->getInfo();
 
                     dump += StringPrintf(INDENT3 "%zu: name='%s', id=%" PRId32 ", displayId=%d, "
-                                                 "portalToDisplayId=%d, paused=%s, focusable=%s, "
+                                                 "paused=%s, focusable=%s, "
                                                  "hasWallpaper=%s, visible=%s, alpha=%.2f, "
                                                  "flags=%s, type=%s, "
                                                  "frame=[%d,%d][%d,%d], globalScale=%f, "
@@ -5037,8 +4996,7 @@
                                                  "applicationInfo.token=%s, "
                                                  "touchableRegion=",
                                          i, windowInfo->name.c_str(), windowInfo->id,
-                                         windowInfo->displayId, windowInfo->portalToDisplayId,
-                                         toString(windowInfo->paused),
+                                         windowInfo->displayId, toString(windowInfo->paused),
                                          toString(windowInfo->focusable),
                                          toString(windowInfo->hasWallpaper),
                                          toString(windowInfo->visible), windowInfo->alpha,
diff --git a/services/inputflinger/dispatcher/InputDispatcher.h b/services/inputflinger/dispatcher/InputDispatcher.h
index 87dd6ee..32a467e 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.h
+++ b/services/inputflinger/dispatcher/InputDispatcher.h
@@ -212,7 +212,6 @@
     sp<android::gui::WindowInfoHandle> findTouchedWindowAtLocked(int32_t displayId, int32_t x,
                                                                  int32_t y, TouchState* touchState,
                                                                  bool addOutsideTargets = false,
-                                                                 bool addPortalWindows = false,
                                                                  bool ignoreDragWindow = false)
             REQUIRES(mLock);
 
@@ -494,9 +493,7 @@
     android::os::InputEventInjectionResult findTouchedWindowTargetsLocked(
             nsecs_t currentTime, const MotionEntry& entry, std::vector<InputTarget>& inputTargets,
             nsecs_t* nextWakeupTime, bool* outConflictingPointerActions) REQUIRES(mLock);
-    std::vector<TouchedMonitor> findTouchedGestureMonitorsLocked(
-            int32_t displayId,
-            const std::vector<sp<android::gui::WindowInfoHandle>>& portalWindows) const
+    std::vector<TouchedMonitor> findTouchedGestureMonitorsLocked(int32_t displayId) const
             REQUIRES(mLock);
     std::vector<TouchedMonitor> selectResponsiveMonitorsLocked(
             const std::vector<TouchedMonitor>& gestureMonitors) const REQUIRES(mLock);
diff --git a/services/inputflinger/dispatcher/LatencyTracker.cpp b/services/inputflinger/dispatcher/LatencyTracker.cpp
index d634dcd..52f189c 100644
--- a/services/inputflinger/dispatcher/LatencyTracker.cpp
+++ b/services/inputflinger/dispatcher/LatencyTracker.cpp
@@ -50,13 +50,12 @@
  * key-value pair. Equivalent to the imaginary std api std::multimap::erase(key, value).
  */
 template <typename K, typename V>
-static void eraseByKeyAndValue(std::multimap<K, V>& map, K key, V value) {
-    auto iterpair = map.equal_range(key);
-
-    for (auto it = iterpair.first; it != iterpair.second; ++it) {
+static void eraseByValue(std::multimap<K, V>& map, const V& value) {
+    for (auto it = map.begin(); it != map.end();) {
         if (it->second == value) {
-            map.erase(it);
-            break;
+            it = map.erase(it);
+        } else {
+            it++;
         }
     }
 }
@@ -76,9 +75,7 @@
         // confuse us by reporting the rest of the timeline for one of them. This should happen
         // rarely, so we won't lose much data
         mTimelines.erase(it);
-        // In case we have another input event with a different id and at the same eventTime,
-        // only erase this specific inputEventId.
-        eraseByKeyAndValue(mEventTimes, eventTime, inputEventId);
+        eraseByValue(mEventTimes, inputEventId);
         return;
     }
     mTimelines.emplace(inputEventId, InputEventTimeline(isDown, eventTime, readTime));
@@ -90,7 +87,8 @@
                                         nsecs_t finishTime) {
     const auto it = mTimelines.find(inputEventId);
     if (it == mTimelines.end()) {
-        // It's possible that an app sends a bad (or late)'Finish' signal, since it's free to do
+        // This could happen if we erased this event when duplicate events were detected. It's
+        // also possible that an app sent a bad (or late) 'Finish' signal, since it's free to do
         // anything in its process. Just drop the report and move on.
         return;
     }
@@ -120,7 +118,8 @@
         std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline) {
     const auto it = mTimelines.find(inputEventId);
     if (it == mTimelines.end()) {
-        // It's possible that an app sends a bad (or late) 'Timeline' signal, since it's free to do
+        // This could happen if we erased this event when duplicate events were detected. It's
+        // also possible that an app sent a bad (or late) 'Timeline' signal, since it's free to do
         // anything in its process. Just drop the report and move on.
         return;
     }
@@ -166,14 +165,6 @@
     }
 }
 
-void LatencyTracker::reportNow() {
-    for (const auto& [inputEventId, timeline] : mTimelines) {
-        mTimelineProcessor->processTimeline(timeline);
-    }
-    mTimelines.clear();
-    mEventTimes.clear();
-}
-
 std::string LatencyTracker::dump(const char* prefix) {
     return StringPrintf("%sLatencyTracker:\n", prefix) +
             StringPrintf("%s  mTimelines.size() = %zu\n", prefix, mTimelines.size()) +
diff --git a/services/inputflinger/dispatcher/LatencyTracker.h b/services/inputflinger/dispatcher/LatencyTracker.h
index 289b8ed..4b0c618 100644
--- a/services/inputflinger/dispatcher/LatencyTracker.h
+++ b/services/inputflinger/dispatcher/LatencyTracker.h
@@ -43,6 +43,12 @@
     LatencyTracker(InputEventTimelineProcessor* processor);
     /**
      * Start keeping track of an event identified by inputEventId. This must be called first.
+     * If duplicate events are encountered (events that have the same eventId), none of them will be
+     * tracked. This is because there is not enough information to correctly track them. The api's
+     * 'trackFinishedEvent' and 'trackGraphicsLatency' only contain the inputEventId, and not the
+     * eventTime. Even if eventTime was provided, there would still be a possibility of having
+     * duplicate events that happen to have the same eventTime and inputEventId. Therefore, we
+     * must drop all duplicate data.
      */
     void trackListener(int32_t inputEventId, bool isDown, nsecs_t eventTime, nsecs_t readTime);
     void trackFinishedEvent(int32_t inputEventId, const sp<IBinder>& connectionToken,
@@ -50,14 +56,6 @@
     void trackGraphicsLatency(int32_t inputEventId, const sp<IBinder>& connectionToken,
                               std::array<nsecs_t, GraphicsTimeline::SIZE> timeline);
 
-    /**
-     * Report all collected events immediately, even if some of them are currently incomplete
-     * and may receive 'trackFinishedEvent' or 'trackGraphicsLatency' calls in the future.
-     * This is useful for tests. Otherwise, tests would have to inject additional "future" events,
-     * which is not convenient.
-     */
-    void reportNow();
-
     std::string dump(const char* prefix);
 
 private:
diff --git a/services/inputflinger/dispatcher/TouchState.cpp b/services/inputflinger/dispatcher/TouchState.cpp
index 20b6ead..b7ed658 100644
--- a/services/inputflinger/dispatcher/TouchState.cpp
+++ b/services/inputflinger/dispatcher/TouchState.cpp
@@ -37,7 +37,6 @@
     source = 0;
     displayId = ADISPLAY_ID_NONE;
     windows.clear();
-    portalWindows.clear();
     gestureMonitors.clear();
 }
 
@@ -48,7 +47,6 @@
     source = other.source;
     displayId = other.displayId;
     windows = other.windows;
-    portalWindows = other.portalWindows;
     gestureMonitors = other.gestureMonitors;
 }
 
@@ -77,16 +75,6 @@
     windows.push_back(touchedWindow);
 }
 
-void TouchState::addPortalWindow(const sp<android::gui::WindowInfoHandle>& windowHandle) {
-    size_t numWindows = portalWindows.size();
-    for (size_t i = 0; i < numWindows; i++) {
-        if (portalWindows[i] == windowHandle) {
-            return;
-        }
-    }
-    portalWindows.push_back(windowHandle);
-}
-
 void TouchState::addGestureMonitors(const std::vector<TouchedMonitor>& newMonitors) {
     const size_t newSize = gestureMonitors.size() + newMonitors.size();
     gestureMonitors.reserve(newSize);
@@ -119,7 +107,6 @@
 
 void TouchState::filterNonMonitors() {
     windows.clear();
-    portalWindows.clear();
 }
 
 sp<WindowInfoHandle> TouchState::getFirstForegroundWindowHandle() const {
diff --git a/services/inputflinger/dispatcher/TouchState.h b/services/inputflinger/dispatcher/TouchState.h
index a4e52b0..579b868 100644
--- a/services/inputflinger/dispatcher/TouchState.h
+++ b/services/inputflinger/dispatcher/TouchState.h
@@ -36,11 +36,6 @@
     int32_t displayId; // id to the display that currently has a touch, others are rejected
     std::vector<TouchedWindow> windows;
 
-    // This collects the portal windows that the touch has gone through. Each portal window
-    // targets a display (embedded display for most cases). With this info, we can add the
-    // monitoring channels of the displays touched.
-    std::vector<sp<android::gui::WindowInfoHandle>> portalWindows;
-
     std::vector<TouchedMonitor> gestureMonitors;
 
     TouchState();
diff --git a/services/inputflinger/tests/LatencyTracker_test.cpp b/services/inputflinger/tests/LatencyTracker_test.cpp
index e7e1937..89c0741 100644
--- a/services/inputflinger/tests/LatencyTracker_test.cpp
+++ b/services/inputflinger/tests/LatencyTracker_test.cpp
@@ -16,6 +16,7 @@
 
 #include "../dispatcher/LatencyTracker.h"
 
+#include <android-base/properties.h>
 #include <binder/Binder.h>
 #include <gtest/gtest.h>
 #include <inttypes.h>
@@ -23,11 +24,16 @@
 
 #define TAG "LatencyTracker_test"
 
+using android::base::HwTimeoutMultiplier;
 using android::inputdispatcher::InputEventTimeline;
 using android::inputdispatcher::LatencyTracker;
 
 namespace android::inputdispatcher {
 
+const std::chrono::duration ANR_TIMEOUT = std::chrono::milliseconds(
+        android::os::IInputConstants::UNMULTIPLIED_DEFAULT_DISPATCHING_TIMEOUT_MILLIS *
+        HwTimeoutMultiplier());
+
 InputEventTimeline getTestTimeline() {
     InputEventTimeline t(
             /*isDown*/ true,
@@ -57,6 +63,8 @@
     }
     void TearDown() override {}
 
+    void triggerEventReporting(nsecs_t lastEventTime);
+
     void assertReceivedTimeline(const InputEventTimeline& timeline);
     /**
      * Timelines can be received in any order (order is not guaranteed). So if we are expecting more
@@ -72,8 +80,17 @@
     std::deque<InputEventTimeline> mReceivedTimelines;
 };
 
+/**
+ * Send an event that would trigger the reporting of all of the events that are at least as old as
+ * the provided 'lastEventTime'.
+ */
+void LatencyTrackerTest::triggerEventReporting(nsecs_t lastEventTime) {
+    const nsecs_t triggerEventTime =
+            lastEventTime + std::chrono::nanoseconds(ANR_TIMEOUT).count() + 1;
+    mTracker->trackListener(1 /*inputEventId*/, true /*isDown*/, triggerEventTime, 3 /*readTime*/);
+}
+
 void LatencyTrackerTest::assertReceivedTimeline(const InputEventTimeline& timeline) {
-    mTracker->reportNow();
     ASSERT_FALSE(mReceivedTimelines.empty());
     const InputEventTimeline& t = mReceivedTimelines.front();
     ASSERT_EQ(timeline, t);
@@ -88,7 +105,6 @@
  * equal element in B, and for every element in B there is an equal element in A.
  */
 void LatencyTrackerTest::assertReceivedTimelines(const std::vector<InputEventTimeline>& timelines) {
-    mTracker->reportNow();
     ASSERT_EQ(timelines.size(), mReceivedTimelines.size());
     for (const InputEventTimeline& expectedTimeline : timelines) {
         bool found = false;
@@ -121,6 +137,7 @@
  */
 TEST_F(LatencyTrackerTest, TrackListener_DoesNotTriggerReporting) {
     mTracker->trackListener(1 /*inputEventId*/, false /*isDown*/, 2 /*eventTime*/, 3 /*readTime*/);
+    triggerEventReporting(2 /*eventTime*/);
     assertReceivedTimeline(InputEventTimeline{false, 2, 3});
 }
 
@@ -130,6 +147,7 @@
 TEST_F(LatencyTrackerTest, TrackFinishedEvent_DoesNotTriggerReporting) {
     mTracker->trackFinishedEvent(1 /*inputEventId*/, connection1, 2 /*deliveryTime*/,
                                  3 /*consumeTime*/, 4 /*finishTime*/);
+    triggerEventReporting(4 /*eventTime*/);
     assertReceivedTimelines({});
 }
 
@@ -141,6 +159,7 @@
     graphicsTimeline[GraphicsTimeline::GPU_COMPLETED_TIME] = 2;
     graphicsTimeline[GraphicsTimeline::PRESENT_TIME] = 3;
     mTracker->trackGraphicsLatency(1 /*inputEventId*/, connection2, graphicsTimeline);
+    triggerEventReporting(3 /*eventTime*/);
     assertReceivedTimelines({});
 }
 
@@ -155,9 +174,30 @@
                                  expectedCT.consumeTime, expectedCT.finishTime);
     mTracker->trackGraphicsLatency(inputEventId, connectionToken, expectedCT.graphicsTimeline);
 
+    triggerEventReporting(expected.eventTime);
     assertReceivedTimeline(expected);
 }
 
+/**
+ * Send 2 events with the same inputEventId, but different eventTime's. Ensure that no crash occurs,
+ * and that the tracker drops such events completely.
+ */
+TEST_F(LatencyTrackerTest, WhenDuplicateEventsAreReported_DoesNotCrash) {
+    constexpr nsecs_t inputEventId = 1;
+    constexpr nsecs_t readTime = 3; // does not matter for this test
+    constexpr bool isDown = true;   // does not matter for this test
+
+    // In the following 2 calls to trackListener, the inputEventId's are the same, but event times
+    // are different.
+    mTracker->trackListener(inputEventId, isDown, 1 /*eventTime*/, readTime);
+    mTracker->trackListener(inputEventId, isDown, 2 /*eventTime*/, readTime);
+
+    triggerEventReporting(2 /*eventTime*/);
+    // Since we sent duplicate input events, the tracker should just delete all of them, because it
+    // does not have enough information to properly track them.
+    assertReceivedTimelines({});
+}
+
 TEST_F(LatencyTrackerTest, MultipleEvents_AreReportedConsistently) {
     constexpr int32_t inputEventId1 = 1;
     InputEventTimeline timeline1(
@@ -204,6 +244,7 @@
     mTracker->trackGraphicsLatency(inputEventId2, connection2,
                                    connectionTimeline2.graphicsTimeline);
     // Now both events should be completed
+    triggerEventReporting(timeline2.eventTime);
     assertReceivedTimelines({timeline1, timeline2});
 }
 
@@ -228,6 +269,7 @@
     mTracker->trackGraphicsLatency(1 /*inputEventId*/, token, expectedCT.graphicsTimeline);
 
     expectedTimelines[0].connectionTimelines.emplace(token, std::move(expectedCT));
+    triggerEventReporting(timeline.eventTime);
     assertReceivedTimelines(expectedTimelines);
 }
 
@@ -246,6 +288,7 @@
     mTracker->trackGraphicsLatency(inputEventId, connection1, expectedCT.graphicsTimeline);
 
     mTracker->trackListener(inputEventId, expected.isDown, expected.eventTime, expected.readTime);
+    triggerEventReporting(expected.eventTime);
     assertReceivedTimeline(
             InputEventTimeline{expected.isDown, expected.eventTime, expected.readTime});
 }
diff --git a/services/inputflinger/tests/fuzzers/Android.bp b/services/inputflinger/tests/fuzzers/Android.bp
new file mode 100644
index 0000000..df4db19
--- /dev/null
+++ b/services/inputflinger/tests/fuzzers/Android.bp
@@ -0,0 +1,45 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_native_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_native_license"],
+}
+
+
+cc_fuzz {
+    name: "inputflinger_latencytracker_fuzzer",
+    defaults: [
+        "inputflinger_defaults",
+    ],
+    include_dirs: [
+        "frameworks/native/services/inputflinger",
+    ],
+    shared_libs: [
+        "libbase",
+        "libbinder",
+        "liblog",
+        "libui",
+        "libutils",
+        "libinput",
+        "libinputflinger",
+    ],
+    srcs: [
+        "LatencyTrackerFuzzer.cpp",
+    ],
+}
diff --git a/services/inputflinger/tests/fuzzers/LatencyTrackerFuzzer.cpp b/services/inputflinger/tests/fuzzers/LatencyTrackerFuzzer.cpp
new file mode 100644
index 0000000..4f066ad
--- /dev/null
+++ b/services/inputflinger/tests/fuzzers/LatencyTrackerFuzzer.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <fuzzer/FuzzedDataProvider.h>
+#include "dispatcher/LatencyTracker.h"
+
+namespace android {
+
+namespace inputdispatcher {
+
+/**
+ * A processor of InputEventTimelines that does nothing with the provided data.
+ */
+class EmptyProcessor : public InputEventTimelineProcessor {
+public:
+    /**
+     * Just ignore the provided timeline
+     */
+    void processTimeline(const InputEventTimeline& timeline) override {
+        for (const auto& [token, connectionTimeline] : timeline.connectionTimelines) {
+            connectionTimeline.isComplete();
+        }
+    };
+};
+
+static sp<IBinder> getConnectionToken(FuzzedDataProvider& fdp,
+                                      std::array<sp<IBinder>, 10>& tokens) {
+    const bool useExistingToken = fdp.ConsumeBool();
+    if (useExistingToken) {
+        return tokens[fdp.ConsumeIntegralInRange<size_t>(0ul, tokens.size() - 1)];
+    }
+    return new BBinder();
+}
+
+extern "C" int LLVMFuzzerTestOneInput(uint8_t* data, size_t size) {
+    FuzzedDataProvider fdp(data, size);
+
+    EmptyProcessor emptyProcessor;
+    LatencyTracker tracker(&emptyProcessor);
+
+    // Make some pre-defined tokens to ensure that some timelines are complete.
+    std::array<sp<IBinder> /*token*/, 10> predefinedTokens;
+    for (size_t i = 0; i < predefinedTokens.size(); i++) {
+        predefinedTokens[i] = new BBinder();
+    }
+
+    // Randomly invoke LatencyTracker api's until randomness is exhausted.
+    while (fdp.remaining_bytes() > 0) {
+        fdp.PickValueInArray<std::function<void()>>({
+                [&]() -> void {
+                    int32_t inputEventId = fdp.ConsumeIntegral<int32_t>();
+                    int32_t isDown = fdp.ConsumeBool();
+                    nsecs_t eventTime = fdp.ConsumeIntegral<nsecs_t>();
+                    nsecs_t readTime = fdp.ConsumeIntegral<nsecs_t>();
+                    tracker.trackListener(inputEventId, isDown, eventTime, readTime);
+                },
+                [&]() -> void {
+                    int32_t inputEventId = fdp.ConsumeIntegral<int32_t>();
+                    sp<IBinder> connectionToken = getConnectionToken(fdp, predefinedTokens);
+                    nsecs_t deliveryTime = fdp.ConsumeIntegral<nsecs_t>();
+                    nsecs_t consumeTime = fdp.ConsumeIntegral<nsecs_t>();
+                    nsecs_t finishTime = fdp.ConsumeIntegral<nsecs_t>();
+                    tracker.trackFinishedEvent(inputEventId, connectionToken, deliveryTime,
+                                               consumeTime, finishTime);
+                },
+                [&]() -> void {
+                    int32_t inputEventId = fdp.ConsumeIntegral<int32_t>();
+                    sp<IBinder> connectionToken = getConnectionToken(fdp, predefinedTokens);
+                    std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline;
+                    for (size_t i = 0; i < graphicsTimeline.size(); i++) {
+                        graphicsTimeline[i] = fdp.ConsumeIntegral<nsecs_t>();
+                    }
+                    tracker.trackGraphicsLatency(inputEventId, connectionToken, graphicsTimeline);
+                },
+        })();
+    }
+
+    return 0;
+}
+
+} // namespace inputdispatcher
+
+} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 71db330..b600fad 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -152,39 +152,10 @@
         return result;
     }
 
-    if (CC_UNLIKELY(mBufferInfo.mBuffer == 0)) {
-        // the texture has not been created yet, this Layer has
-        // in fact never been drawn into. This happens frequently with
-        // SurfaceView because the WindowManager can't know when the client
-        // has drawn the first time.
-
-        // If there is nothing under us, we paint the screen in black, otherwise
-        // we just skip this update.
-
-        // figure out if there is something below us
-        Region under;
-        bool finished = false;
-        mFlinger->mDrawingState.traverseInZOrder([&](Layer* layer) {
-            if (finished || layer == static_cast<BufferLayer const*>(this)) {
-                finished = true;
-                return;
-            }
-
-            under.orSelf(layer->getScreenBounds());
-        });
-        // if not everything below us is covered, we plug the holes!
-        Region holes(targetSettings.clip.subtract(under));
-        if (!holes.isEmpty()) {
-            targetSettings.clearRegion.orSelf(holes);
-        }
-
-        if (mSidebandStream != nullptr) {
-            // For surfaceview of tv sideband, there is no activeBuffer
-            // in bufferqueue, we need return LayerSettings.
-            return result;
-        } else {
-            return std::nullopt;
-        }
+    if (CC_UNLIKELY(mBufferInfo.mBuffer == 0) && mSidebandStream != nullptr) {
+        // For surfaceview of tv sideband, there is no activeBuffer
+        // in bufferqueue, we need return LayerSettings.
+        return result;
     }
     const bool blackOutLayer = (isProtected() && !targetSettings.supportsProtectedContent) ||
             ((isSecure() || isProtected()) && !targetSettings.isSecure);
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index 6b6d434..2fa8936 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -153,11 +153,12 @@
 }
 
 bool BufferQueueLayer::framePresentTimeIsCurrent(nsecs_t expectedPresentTime) const {
+    Mutex::Autolock lock(mQueueItemLock);
+
     if (!hasFrameUpdate() || isRemovedFromCurrentState()) {
         return true;
     }
 
-    Mutex::Autolock lock(mQueueItemLock);
     return mQueueItems[0].item.mTimestamp <= expectedPresentTime;
 }
 
@@ -269,13 +270,15 @@
         // and return early
         if (queuedBuffer) {
             Mutex::Autolock lock(mQueueItemLock);
-            mConsumer->mergeSurfaceDamage(mQueueItems[0].item.mSurfaceDamage);
-            mFlinger->mTimeStats->removeTimeRecord(layerId, mQueueItems[0].item.mFrameNumber);
-            if (mQueueItems[0].surfaceFrame) {
-                addSurfaceFrameDroppedForBuffer(mQueueItems[0].surfaceFrame);
+            if (mQueuedFrames > 0) {
+                mConsumer->mergeSurfaceDamage(mQueueItems[0].item.mSurfaceDamage);
+                mFlinger->mTimeStats->removeTimeRecord(layerId, mQueueItems[0].item.mFrameNumber);
+                if (mQueueItems[0].surfaceFrame) {
+                    addSurfaceFrameDroppedForBuffer(mQueueItems[0].surfaceFrame);
+                }
+                mQueueItems.erase(mQueueItems.begin());
+                mQueuedFrames--;
             }
-            mQueueItems.erase(mQueueItems.begin());
-            mQueuedFrames--;
         }
         return BAD_VALUE;
     } else if (updateResult != NO_ERROR || mUpdateTexImageFailed) {
@@ -305,6 +308,7 @@
         return BAD_VALUE;
     }
 
+    bool more_frames_pending = false;
     if (queuedBuffer) {
         // Autolock scope
         auto currentFrameNumber = mConsumer->getFrameNumber();
@@ -313,7 +317,7 @@
 
         // Remove any stale buffers that have been dropped during
         // updateTexImage
-        while (mQueueItems[0].item.mFrameNumber != currentFrameNumber) {
+        while (mQueuedFrames > 0 && mQueueItems[0].item.mFrameNumber != currentFrameNumber) {
             mConsumer->mergeSurfaceDamage(mQueueItems[0].item.mSurfaceDamage);
             mFlinger->mTimeStats->removeTimeRecord(layerId, mQueueItems[0].item.mFrameNumber);
             if (mQueueItems[0].surfaceFrame) {
@@ -334,11 +338,12 @@
                                               latchTime);
         }
         mQueueItems.erase(mQueueItems.begin());
+        more_frames_pending = (mQueuedFrames.fetch_sub(1) > 1);
     }
 
     // Decrement the queued-frames count.  Signal another event if we
     // have more frames pending.
-    if ((queuedBuffer && mQueuedFrames.fetch_sub(1) > 1) || mAutoRefresh) {
+    if ((queuedBuffer && more_frames_pending) || mAutoRefresh) {
         mFlinger->signalLayerUpdate();
     }
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/DisplayCreationArgs.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/DisplayCreationArgs.h
index 14eddb1..526e7da 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/DisplayCreationArgs.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/DisplayCreationArgs.h
@@ -40,7 +40,7 @@
     std::optional<ui::DisplayConnectionType> connectionType;
 
     // Size of the display in pixels
-    ui::Size pixels = ui::Size::INVALID;
+    ui::Size pixels = ui::kInvalidSize;
 
     // True if this display should be considered secure
     bool isSecure = false;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
index e51019a..6d1017f 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
@@ -115,10 +115,6 @@
         // If set to true, the target buffer has protected content support.
         const bool supportsProtectedContent;
 
-        // Modified by each call to prepareClientComposition to indicate the
-        // region of the target buffer that should be cleared.
-        Region& clearRegion;
-
         // Viewport of the target being rendered to. This is used to determine
         // the shadow light position.
         const Rect& viewport;
@@ -177,11 +173,10 @@
 
 static inline bool operator==(const LayerFE::ClientCompositionTargetSettings& lhs,
                               const LayerFE::ClientCompositionTargetSettings& rhs) {
-    return lhs.clip.hasSameRects(rhs.clip) &&
-            lhs.needsFiltering == rhs.needsFiltering && lhs.isSecure == rhs.isSecure &&
+    return lhs.clip.hasSameRects(rhs.clip) && lhs.needsFiltering == rhs.needsFiltering &&
+            lhs.isSecure == rhs.isSecure &&
             lhs.supportsProtectedContent == rhs.supportsProtectedContent &&
-            lhs.clearRegion.hasSameRects(rhs.clearRegion) && lhs.viewport == rhs.viewport &&
-            lhs.dataspace == rhs.dataspace &&
+            lhs.viewport == rhs.viewport && lhs.dataspace == rhs.dataspace &&
             lhs.realContentIsVisible == rhs.realContentIsVisible &&
             lhs.clearContent == rhs.clearContent;
 }
@@ -202,8 +197,6 @@
     *os << "\n    .needsFiltering = " << settings.needsFiltering;
     *os << "\n    .isSecure = " << settings.isSecure;
     *os << "\n    .supportsProtectedContent = " << settings.supportsProtectedContent;
-    *os << "\n    .clearRegion = ";
-    PrintTo(settings.clearRegion, os);
     *os << "\n    .viewport = ";
     PrintTo(settings.viewport, os);
     *os << "\n    .dataspace = ";
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
index 1416b1e..e2b07f0 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
@@ -291,7 +291,7 @@
     virtual bool getSkipColorTransform() const = 0;
     virtual FrameFences presentAndGetFrameFences() = 0;
     virtual std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
-            bool supportsProtectedContent, Region& clearRegion, ui::Dataspace outputDataspace) = 0;
+            bool supportsProtectedContent, ui::Dataspace outputDataspace) = 0;
     virtual void appendRegionFlashRequests(
             const Region& flashRegion,
             std::vector<LayerFE::LayerSettings>& clientCompositionLayers) = 0;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
index f832084..2e40487 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
@@ -110,8 +110,7 @@
     bool getSkipColorTransform() const override;
     compositionengine::Output::FrameFences presentAndGetFrameFences() override;
     std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
-            bool supportsProtectedContent, Region& clearRegion,
-            ui::Dataspace outputDataspace) override;
+            bool supportsProtectedContent, ui::Dataspace outputDataspace) override;
     void appendRegionFlashRequests(const Region&, std::vector<LayerFE::LayerSettings>&) override;
     void setExpensiveRenderingExpected(bool enabled) override;
     void dumpBase(std::string&) const;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
index 8e777e3..60ff4b1 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
@@ -112,8 +112,8 @@
     MOCK_METHOD1(renderCachedSets, void(const CompositionRefreshArgs&));
     MOCK_METHOD0(presentAndGetFrameFences, compositionengine::Output::FrameFences());
 
-    MOCK_METHOD3(generateClientCompositionRequests,
-                 std::vector<LayerFE::LayerSettings>(bool, Region&, ui::Dataspace));
+    MOCK_METHOD2(generateClientCompositionRequests,
+                 std::vector<LayerFE::LayerSettings>(bool, ui::Dataspace));
     MOCK_METHOD2(appendRegionFlashRequests,
                  void(const Region&, std::vector<LayerFE::LayerSettings>&));
     MOCK_METHOD1(setExpensiveRenderingExpected, void(bool));
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index cafcb40..3c3c7f3 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -1069,13 +1069,9 @@
         clientCompositionDisplay.colorTransform = outputState.colorTransformMatrix;
     }
 
-    // Note: Updated by generateClientCompositionRequests
-    clientCompositionDisplay.clearRegion = Region::INVALID_REGION;
-
     // Generate the client composition requests for the layers on this output.
     std::vector<LayerFE::LayerSettings> clientCompositionLayers =
             generateClientCompositionRequests(supportsProtectedContent,
-                                              clientCompositionDisplay.clearRegion,
                                               clientCompositionDisplay.outputDataspace);
     appendRegionFlashRequests(debugRegion, clientCompositionLayers);
 
@@ -1143,15 +1139,13 @@
 }
 
 std::vector<LayerFE::LayerSettings> Output::generateClientCompositionRequests(
-        bool supportsProtectedContent, Region& clearRegion, ui::Dataspace outputDataspace) {
+        bool supportsProtectedContent, ui::Dataspace outputDataspace) {
     std::vector<LayerFE::LayerSettings> clientCompositionLayers;
     ALOGV("Rendering client layers");
 
     const auto& outputState = getState();
     const Region viewportRegion(outputState.layerStackSpace.content);
     bool firstLayer = true;
-    // Used when a layer clears part of the buffer.
-    Region stubRegion;
 
     bool disableBlurs = false;
     sp<GraphicBuffer> previousOverrideBuffer = nullptr;
@@ -1213,7 +1207,6 @@
                                                outputState.needsFiltering,
                                        .isSecure = outputState.isSecure,
                                        .supportsProtectedContent = supportsProtectedContent,
-                                       .clearRegion = clientComposition ? clearRegion : stubRegion,
                                        .viewport = outputState.layerStackSpace.content,
                                        .dataspace = outputDataspace,
                                        .realContentIsVisible = realContentIsVisible,
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
index b24274e..b82bdbc 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
@@ -171,13 +171,11 @@
             .orientation = orientation,
     };
 
-    Region clearRegion = Region::INVALID_REGION;
     LayerFE::ClientCompositionTargetSettings targetSettings{
             .clip = Region(viewport),
             .needsFiltering = false,
             .isSecure = true,
             .supportsProtectedContent = false,
-            .clearRegion = clearRegion,
             .viewport = viewport,
             .dataspace = outputDataspace,
             .realContentIsVisible = true,
diff --git a/services/surfaceflinger/CompositionEngine/tests/DisplayTest.cpp b/services/surfaceflinger/CompositionEngine/tests/DisplayTest.cpp
index c037cc6..72b16e0 100644
--- a/services/surfaceflinger/CompositionEngine/tests/DisplayTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/DisplayTest.cpp
@@ -60,7 +60,7 @@
 constexpr HalVirtualDisplayId HAL_VIRTUAL_DISPLAY_ID{456u};
 constexpr GpuVirtualDisplayId GPU_VIRTUAL_DISPLAY_ID{789u};
 
-const ui::Size DEFAULT_RESOLUTION{1920, 1080};
+constexpr ui::Size DEFAULT_RESOLUTION{1920, 1080};
 constexpr uint32_t DEFAULT_LAYER_STACK = 42;
 
 struct Layer {
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
index a195e58..65c97b7 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWComposer.h
@@ -51,6 +51,7 @@
                  bool(HalVirtualDisplayId, ui::Size, ui::PixelFormat*,
                       std::optional<PhysicalDisplayId>));
     MOCK_METHOD2(allocatePhysicalDisplay, void(hal::HWDisplayId, PhysicalDisplayId));
+
     MOCK_METHOD1(createLayer, std::shared_ptr<HWC2::Layer>(HalDisplayId));
     MOCK_METHOD5(getDeviceCompositionChanges,
                  status_t(HalDisplayId, bool, std::chrono::steady_clock::time_point,
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index ee73cfc..c3185e9 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -2992,8 +2992,8 @@
         // Sets up the helper functions called by the function under test to use
         // mock implementations.
         MOCK_CONST_METHOD0(getSkipColorTransform, bool());
-        MOCK_METHOD3(generateClientCompositionRequests,
-                     std::vector<LayerFE::LayerSettings>(bool, Region&, ui::Dataspace));
+        MOCK_METHOD2(generateClientCompositionRequests,
+                     std::vector<LayerFE::LayerSettings>(bool, ui::Dataspace));
         MOCK_METHOD2(appendRegionFlashRequests,
                      void(const Region&, std::vector<LayerFE::LayerSettings>&));
         MOCK_METHOD1(setExpensiveRenderingExpected, void(bool));
@@ -3142,7 +3142,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
@@ -3165,7 +3165,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(
@@ -3195,7 +3195,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(
@@ -3223,7 +3223,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
@@ -3252,7 +3252,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
@@ -3281,7 +3281,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
@@ -3316,7 +3316,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>{r1, r2}))
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>{r1, r3}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
@@ -3339,7 +3339,7 @@
     OutputComposeSurfacesTest_UsesExpectedDisplaySettings() {
         EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
         EXPECT_CALL(mRenderEngine, isProtected()).WillRepeatedly(Return(false));
-        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
                 .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
                 .WillRepeatedly(Return());
@@ -3391,7 +3391,7 @@
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
+                                            kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3402,7 +3402,7 @@
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
+                                            kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3413,7 +3413,7 @@
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace,
-                                            kDefaultColorTransformMat, Region::INVALID_REGION,
+                                            kDefaultColorTransformMat,
                                             kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
@@ -3425,7 +3425,7 @@
             .andIfSkipColorTransform(false)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace,
-                                            kDefaultColorTransformMat, Region::INVALID_REGION,
+                                            kDefaultColorTransformMat,
                                             kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
@@ -3438,7 +3438,7 @@
             .andIfSkipColorTransform(true)
             .thenExpectDisplaySettingsUsed({kDefaultOutputDestinationClip, kDefaultOutputViewport,
                                             kDefaultMaxLuminance, kDefaultOutputDataspace, mat4(),
-                                            Region::INVALID_REGION, kDefaultOutputOrientationFlags})
+                                            kDefaultOutputOrientationFlags})
             .execute()
             .expectAFenceWasReturned();
 }
@@ -3469,7 +3469,7 @@
 
         EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
 
-        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, _))
+        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _))
                 .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
                 .WillRepeatedly(Return());
@@ -3590,7 +3590,7 @@
 TEST_F(OutputComposeSurfacesTest_SetsExpensiveRendering, IfExepensiveOutputDataspaceIsUsed) {
     mOutput.mState.dataspace = kExpensiveOutputDataspace;
 
-    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kExpensiveOutputDataspace))
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kExpensiveOutputDataspace))
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>{}));
 
     // For this test, we also check the call order of key functions.
@@ -3612,7 +3612,7 @@
         EXPECT_CALL(mLayer.outputLayer,
                     writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0,
                                     /*zIsOverridden*/ false, /*isPeekingThrough*/ false));
-        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+        EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace))
                 .WillOnce(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _, _)).WillOnce(Return(NO_ERROR));
         EXPECT_CALL(mOutput, getOutputLayerCount()).WillRepeatedly(Return(1u));
@@ -3652,10 +3652,9 @@
     struct OutputPartialMock : public OutputPartialMockBase {
         // compositionengine::Output overrides
         std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
-                bool supportsProtectedContent, Region& clearRegion,
-                ui::Dataspace dataspace) override {
+                bool supportsProtectedContent, ui::Dataspace dataspace) override {
             return impl::Output::generateClientCompositionRequests(supportsProtectedContent,
-                                                                   clearRegion, dataspace);
+                                                                   dataspace);
         }
     };
 
@@ -3739,11 +3738,9 @@
     EXPECT_CALL(mLayers[1].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
     EXPECT_CALL(mLayers[2].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     EXPECT_EQ(0u, requests.size());
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers, requiresVisibleRegionAfterViewportClip) {
@@ -3751,11 +3748,9 @@
     mLayers[1].mOutputLayerState.visibleRegion = Region(Rect(4000, 0, 4010, 10));
     mLayers[2].mOutputLayerState.visibleRegion = Region(Rect(-10, -10, 0, 0));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     EXPECT_EQ(0u, requests.size());
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers, gathersClientCompositionRequests) {
@@ -3770,16 +3765,13 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>(
                     {mShadowSettings, mLayers[2].mLayerSettings})));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(3u, requests.size());
     EXPECT_EQ(mLayers[1].mLayerSettings, requests[0]);
     EXPECT_EQ(mShadowSettings, requests[1]);
     EXPECT_EQ(mLayers[2].mLayerSettings, requests[2]);
 
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
-
     // Check that a timestamp was set for the layers that generated requests
     EXPECT_TRUE(0 == mLayers[0].mOutputLayerState.clientCompositionTimestamp);
     EXPECT_TRUE(0 != mLayers[1].mOutputLayerState.clientCompositionTimestamp);
@@ -3810,16 +3802,13 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>(
                     {mShadowSettings, mLayers[2].mLayerSettings})));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(3u, requests.size());
     EXPECT_EQ(mLayers[1].mLayerSettings, requests[0]);
     EXPECT_EQ(mShadowSettings, requests[1]);
     EXPECT_EQ(mLayers[2].mLayerSettings, requests[2]);
 
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
-
     // Check that a timestamp was set for the layers that generated requests
     EXPECT_TRUE(0 == mLayers[0].mOutputLayerState.clientCompositionTimestamp);
     EXPECT_TRUE(0 != mLayers[1].mOutputLayerState.clientCompositionTimestamp);
@@ -3843,13 +3832,10 @@
     EXPECT_CALL(*mLayers[2].mLayerFE, prepareClientCompositionList(_))
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>({mLayers[2].mLayerSettings})));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
     EXPECT_EQ(mLayers[2].mLayerSettings, requests[0]);
-
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -3869,13 +3855,10 @@
     EXPECT_CALL(*mLayers[2].mLayerFE, prepareClientCompositionList(_))
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>({mLayers[2].mLayerSettings})));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
     EXPECT_EQ(mLayers[2].mLayerSettings, requests[0]);
-
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers, clearsHWCLayersIfOpaqueAndNotFirst) {
@@ -3896,15 +3879,12 @@
     mLayers[0].mLayerFEState.isOpaque = true;
     mLayers[1].mLayerFEState.isOpaque = true;
     mLayers[2].mLayerFEState.isOpaque = true;
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-    Region stubRegion;
 
     compositionengine::LayerFE::ClientCompositionTargetSettings layer1TargetSettings{
             Region(kDisplayFrame),
             false,      /* needs filtering */
             false,      /* secure */
             false,      /* supports protected content */
-            stubRegion, /* clear region */
             kDisplayViewport,
             kDisplayDataspace,
             false /* realContentIsVisible */,
@@ -3916,7 +3896,6 @@
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -3936,15 +3915,13 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>({mLayers[2].mLayerSettings})));
 
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(2u, requests.size());
 
     // The second layer is expected to be rendered as alpha=0 black with no blending
     EXPECT_EQ(mBlackoutSettings, requests[0]);
 
     EXPECT_EQ(mLayers[2].mLayerSettings, requests[1]);
-
-    EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -3953,14 +3930,11 @@
     mLayers[1].mOutputLayerState.visibleRegion = Region(Rect(-10, -10, 30, 30));
     mLayers[2].mOutputLayerState.visibleRegion = Region(Rect(-10, 0, 40, 4000));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-
     compositionengine::LayerFE::ClientCompositionTargetSettings layer0TargetSettings{
             Region(Rect(10, 10, 20, 20)),
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -3972,7 +3946,6 @@
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -3984,7 +3957,6 @@
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4001,7 +3973,7 @@
 
     static_cast<void>(
             mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                      accumClearRegion, kDisplayDataspace));
+                                                      kDisplayDataspace));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -4009,14 +3981,11 @@
     mOutput.mState.needsFiltering = false;
     EXPECT_CALL(mLayers[0].mOutputLayer, needsFiltering()).WillRepeatedly(Return(true));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-
     compositionengine::LayerFE::ClientCompositionTargetSettings layer0TargetSettings{
             Region(kDisplayFrame),
             true,  /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4028,7 +3997,6 @@
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4040,7 +4008,6 @@
             false, /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4057,7 +4024,7 @@
 
     static_cast<void>(
             mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                      accumClearRegion, kDisplayDataspace));
+                                                      kDisplayDataspace));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -4065,14 +4032,11 @@
     mOutput.mState.needsFiltering = true;
     EXPECT_CALL(mLayers[0].mOutputLayer, needsFiltering()).WillRepeatedly(Return(true));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-
     compositionengine::LayerFE::ClientCompositionTargetSettings layer0TargetSettings{
             Region(kDisplayFrame),
             true,  /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4085,7 +4049,6 @@
             true,  /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4097,7 +4060,6 @@
             true,  /* needs filtering */
             false, /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4114,21 +4076,18 @@
 
     static_cast<void>(
             mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                      accumClearRegion, kDisplayDataspace));
+                                                      kDisplayDataspace));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
        wholeOutputSecurityUsedToGenerateRequests) {
     mOutput.mState.isSecure = true;
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-
     compositionengine::LayerFE::ClientCompositionTargetSettings layer0TargetSettings{
             Region(kDisplayFrame),
             false, /* needs filtering */
             true,  /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4140,7 +4099,6 @@
             false, /* needs filtering */
             true,  /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4152,7 +4110,6 @@
             false, /* needs filtering */
             true,  /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4169,19 +4126,17 @@
 
     static_cast<void>(
             mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                      accumClearRegion, kDisplayDataspace));
+                                                      kDisplayDataspace));
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
        protectedContentSupportUsedToGenerateRequests) {
-    Region accumClearRegion(Rect(10, 11, 12, 13));
 
     compositionengine::LayerFE::ClientCompositionTargetSettings layer0TargetSettings{
             Region(kDisplayFrame),
             false, /* needs filtering */
             false, /* secure */
             true,  /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4193,7 +4148,6 @@
             false, /* needs filtering */
             false, /* secure */
             true,  /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4205,7 +4159,6 @@
             false, /* needs filtering */
             false, /* secure */
             true,  /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4221,7 +4174,6 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>()));
 
     static_cast<void>(mOutput.generateClientCompositionRequests(true /* supportsProtectedContent */,
-                                                                accumClearRegion,
                                                                 kDisplayDataspace));
 }
 
@@ -4336,14 +4288,11 @@
     EXPECT_CALL(mOutput, getOutputLayerOrderedByZByIndex(1u))
             .WillRepeatedly(Return(&rightLayer.mOutputLayer));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
-
     compositionengine::LayerFE::ClientCompositionTargetSettings leftLayerSettings{
             Region(Rect(0, 0, 1000, 1000)),
             false, /* needs filtering */
             true,  /* secure */
             true,  /* supports protected content */
-            accumClearRegion,
             kPortraitViewport,
             kOutputDataspace,
             true /* realContentIsVisible */,
@@ -4361,7 +4310,6 @@
             false, /* needs filtering */
             true,  /* secure */
             true,  /* supports protected content */
-            accumClearRegion,
             kPortraitViewport,
             kOutputDataspace,
             true /* realContentIsVisible */,
@@ -4375,8 +4323,8 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>({rightLayer.mLayerSettings})));
 
     constexpr bool supportsProtectedContent = true;
-    auto requests = mOutput.generateClientCompositionRequests(supportsProtectedContent,
-                                                              accumClearRegion, kOutputDataspace);
+    auto requests =
+            mOutput.generateClientCompositionRequests(supportsProtectedContent, kOutputDataspace);
     ASSERT_EQ(2u, requests.size());
     EXPECT_EQ(leftLayer.mLayerSettings, requests[0]);
     EXPECT_EQ(rightLayer.mLayerSettings, requests[1]);
@@ -4389,13 +4337,11 @@
     const Region kShadowRegion = Region(kContentWithShadow).subtract(kContent);
     const Region kPartialShadowRegion = Region(kContentWithShadow).subtract(Rect(40, 40, 60, 80));
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     compositionengine::LayerFE::ClientCompositionTargetSettings layer2Settings{
             Region(Rect(60, 40, 70, 80)).merge(Rect(40, 80, 70, 90)), /* visible region */
             false,                                                    /* needs filtering */
             false,                                                    /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             false /* realContentIsVisible */,
@@ -4415,7 +4361,7 @@
             .WillOnce(Return(std::vector<LayerFE::LayerSettings>({mShadowSettings})));
 
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
 
     EXPECT_EQ(mShadowSettings, requests[0]);
@@ -4435,13 +4381,11 @@
     mLayers[2].mOutputLayerState.visibleRegion = kPartialContentWithPartialShadowRegion;
     mLayers[2].mOutputLayerState.shadowRegion = kShadowRegion;
 
-    Region accumClearRegion(Rect(10, 11, 12, 13));
     compositionengine::LayerFE::ClientCompositionTargetSettings layer2Settings{
             Region(Rect(50, 40, 70, 80)).merge(Rect(40, 80, 70, 90)), /* visible region */
             false,                                                    /* needs filtering */
             false,                                                    /* secure */
             false, /* supports protected content */
-            accumClearRegion,
             kDisplayViewport,
             kDisplayDataspace,
             true /* realContentIsVisible */,
@@ -4456,7 +4400,7 @@
                     {mShadowSettings, mLayers[2].mLayerSettings})));
 
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
-                                                              accumClearRegion, kDisplayDataspace);
+                                                              kDisplayDataspace);
     ASSERT_EQ(2u, requests.size());
 
     EXPECT_EQ(mShadowSettings, requests[0]);
diff --git a/services/surfaceflinger/CompositionEngine/tests/RenderSurfaceTest.cpp b/services/surfaceflinger/CompositionEngine/tests/RenderSurfaceTest.cpp
index 5090bb2..431cc93 100644
--- a/services/surfaceflinger/CompositionEngine/tests/RenderSurfaceTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/RenderSurfaceTest.cpp
@@ -35,7 +35,7 @@
 
 constexpr int32_t DEFAULT_DISPLAY_WIDTH = 1920;
 constexpr int32_t DEFAULT_DISPLAY_HEIGHT = 1080;
-constexpr DisplayId DEFAULT_DISPLAY_ID = PhysicalDisplayId(123u);
+constexpr DisplayId DEFAULT_DISPLAY_ID = PhysicalDisplayId::fromPort(123u);
 const std::string DEFAULT_DISPLAY_NAME = "Mock Display";
 
 using testing::_;
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 4d435c7..afd12b5 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -354,16 +354,4 @@
     DisplayModeId activeModeId;
 };
 
-// Predicates for display lookup.
-
-struct WithLayerStack {
-    explicit WithLayerStack(ui::LayerStack layerStack) : layerStack(layerStack) {}
-
-    bool operator()(const DisplayDevice& display) const {
-        return display.getLayerStack() == layerStack;
-    }
-
-    ui::LayerStack layerStack;
-};
-
 } // namespace android
diff --git a/services/surfaceflinger/RefreshRateOverlay.cpp b/services/surfaceflinger/RefreshRateOverlay.cpp
index 8704c88..2adfe14 100644
--- a/services/surfaceflinger/RefreshRateOverlay.cpp
+++ b/services/surfaceflinger/RefreshRateOverlay.cpp
@@ -25,6 +25,10 @@
 #include "Client.h"
 #include "Layer.h"
 
+#include <SkBlendMode.h>
+#include <SkPaint.h>
+#include <SkRect.h>
+#include <SkSurface.h>
 #include <gui/IProducerListener.h>
 
 #undef LOG_TAG
@@ -32,85 +36,64 @@
 
 namespace android {
 
-void RefreshRateOverlay::SevenSegmentDrawer::drawRect(const Rect& r, const half4& color,
-                                                      const sp<GraphicBuffer>& buffer,
-                                                      uint8_t* pixels) {
-    for (int32_t j = r.top; j < r.bottom; j++) {
-        if (j >= buffer->getHeight()) {
-            break;
-        }
-
-        for (int32_t i = r.left; i < r.right; i++) {
-            if (i >= buffer->getWidth()) {
-                break;
-            }
-
-            uint8_t* iter = pixels + 4 * (i + (buffer->getStride() * j));
-            iter[0] = uint8_t(color.r * 255);
-            iter[1] = uint8_t(color.g * 255);
-            iter[2] = uint8_t(color.b * 255);
-            iter[3] = uint8_t(color.a * 255);
-        }
-    }
-}
-
-void RefreshRateOverlay::SevenSegmentDrawer::drawSegment(Segment segment, int left,
-                                                         const half4& color,
-                                                         const sp<GraphicBuffer>& buffer,
-                                                         uint8_t* pixels) {
-    const Rect rect = [&]() {
+void RefreshRateOverlay::SevenSegmentDrawer::drawSegment(Segment segment, int left, SkColor& color,
+                                                         SkCanvas& canvas) {
+    const SkRect rect = [&]() {
         switch (segment) {
             case Segment::Upper:
-                return Rect(left, 0, left + DIGIT_WIDTH, DIGIT_SPACE);
+                return SkRect::MakeLTRB(left, 0, left + DIGIT_WIDTH, DIGIT_SPACE);
             case Segment::UpperLeft:
-                return Rect(left, 0, left + DIGIT_SPACE, DIGIT_HEIGHT / 2);
+                return SkRect::MakeLTRB(left, 0, left + DIGIT_SPACE, DIGIT_HEIGHT / 2);
             case Segment::UpperRight:
-                return Rect(left + DIGIT_WIDTH - DIGIT_SPACE, 0, left + DIGIT_WIDTH,
-                            DIGIT_HEIGHT / 2);
+                return SkRect::MakeLTRB(left + DIGIT_WIDTH - DIGIT_SPACE, 0, left + DIGIT_WIDTH,
+                                        DIGIT_HEIGHT / 2);
             case Segment::Middle:
-                return Rect(left, DIGIT_HEIGHT / 2 - DIGIT_SPACE / 2, left + DIGIT_WIDTH,
-                            DIGIT_HEIGHT / 2 + DIGIT_SPACE / 2);
+                return SkRect::MakeLTRB(left, DIGIT_HEIGHT / 2 - DIGIT_SPACE / 2,
+                                        left + DIGIT_WIDTH, DIGIT_HEIGHT / 2 + DIGIT_SPACE / 2);
             case Segment::LowerLeft:
-                return Rect(left, DIGIT_HEIGHT / 2, left + DIGIT_SPACE, DIGIT_HEIGHT);
+                return SkRect::MakeLTRB(left, DIGIT_HEIGHT / 2, left + DIGIT_SPACE, DIGIT_HEIGHT);
             case Segment::LowerRight:
-                return Rect(left + DIGIT_WIDTH - DIGIT_SPACE, DIGIT_HEIGHT / 2, left + DIGIT_WIDTH,
-                            DIGIT_HEIGHT);
-            case Segment::Buttom:
-                return Rect(left, DIGIT_HEIGHT - DIGIT_SPACE, left + DIGIT_WIDTH, DIGIT_HEIGHT);
+                return SkRect::MakeLTRB(left + DIGIT_WIDTH - DIGIT_SPACE, DIGIT_HEIGHT / 2,
+                                        left + DIGIT_WIDTH, DIGIT_HEIGHT);
+            case Segment::Bottom:
+                return SkRect::MakeLTRB(left, DIGIT_HEIGHT - DIGIT_SPACE, left + DIGIT_WIDTH,
+                                        DIGIT_HEIGHT);
         }
     }();
 
-    drawRect(rect, color, buffer, pixels);
+    SkPaint paint;
+    paint.setColor(color);
+    paint.setBlendMode(SkBlendMode::kSrc);
+    canvas.drawRect(rect, paint);
 }
 
-void RefreshRateOverlay::SevenSegmentDrawer::drawDigit(int digit, int left, const half4& color,
-                                                       const sp<GraphicBuffer>& buffer,
-                                                       uint8_t* pixels) {
+void RefreshRateOverlay::SevenSegmentDrawer::drawDigit(int digit, int left, SkColor& color,
+                                                       SkCanvas& canvas) {
     if (digit < 0 || digit > 9) return;
 
     if (digit == 0 || digit == 2 || digit == 3 || digit == 5 || digit == 6 || digit == 7 ||
         digit == 8 || digit == 9)
-        drawSegment(Segment::Upper, left, color, buffer, pixels);
+        drawSegment(Segment::Upper, left, color, canvas);
     if (digit == 0 || digit == 4 || digit == 5 || digit == 6 || digit == 8 || digit == 9)
-        drawSegment(Segment::UpperLeft, left, color, buffer, pixels);
+        drawSegment(Segment::UpperLeft, left, color, canvas);
     if (digit == 0 || digit == 1 || digit == 2 || digit == 3 || digit == 4 || digit == 7 ||
         digit == 8 || digit == 9)
-        drawSegment(Segment::UpperRight, left, color, buffer, pixels);
+        drawSegment(Segment::UpperRight, left, color, canvas);
     if (digit == 2 || digit == 3 || digit == 4 || digit == 5 || digit == 6 || digit == 8 ||
         digit == 9)
-        drawSegment(Segment::Middle, left, color, buffer, pixels);
+        drawSegment(Segment::Middle, left, color, canvas);
     if (digit == 0 || digit == 2 || digit == 6 || digit == 8)
-        drawSegment(Segment::LowerLeft, left, color, buffer, pixels);
+        drawSegment(Segment::LowerLeft, left, color, canvas);
     if (digit == 0 || digit == 1 || digit == 3 || digit == 4 || digit == 5 || digit == 6 ||
         digit == 7 || digit == 8 || digit == 9)
-        drawSegment(Segment::LowerRight, left, color, buffer, pixels);
+        drawSegment(Segment::LowerRight, left, color, canvas);
     if (digit == 0 || digit == 2 || digit == 3 || digit == 5 || digit == 6 || digit == 8 ||
         digit == 9)
-        drawSegment(Segment::Buttom, left, color, buffer, pixels);
+        drawSegment(Segment::Bottom, left, color, canvas);
 }
 
-std::vector<sp<GraphicBuffer>> RefreshRateOverlay::SevenSegmentDrawer::drawNumber(
-        int number, const half4& color, bool showSpinner) {
+std::vector<sp<GraphicBuffer>> RefreshRateOverlay::SevenSegmentDrawer::draw(
+        int number, SkColor& color, ui::Transform::RotationFlags rotation, bool showSpinner) {
     if (number < 0 || number > 1000) return {};
 
     const auto hundreds = number / 100;
@@ -120,55 +103,76 @@
     std::vector<sp<GraphicBuffer>> buffers;
     const auto loopCount = showSpinner ? 6 : 1;
     for (int i = 0; i < loopCount; i++) {
+        // Pre-rotate the buffer before it reaches SurfaceFlinger.
+        SkMatrix canvasTransform = SkMatrix();
+        auto [bufferWidth, bufferHeight] = [&] {
+            switch (rotation) {
+                case ui::Transform::ROT_90:
+                    canvasTransform.setTranslate(BUFFER_HEIGHT, 0);
+                    canvasTransform.preRotate(90);
+                    return std::make_tuple(BUFFER_HEIGHT, BUFFER_WIDTH);
+                case ui::Transform::ROT_270:
+                    canvasTransform.setRotate(270, BUFFER_WIDTH / 2.0, BUFFER_WIDTH / 2.0);
+                    return std::make_tuple(BUFFER_HEIGHT, BUFFER_WIDTH);
+                default:
+                    return std::make_tuple(BUFFER_WIDTH, BUFFER_HEIGHT);
+            }
+        }();
         sp<GraphicBuffer> buffer =
-                new GraphicBuffer(BUFFER_WIDTH, BUFFER_HEIGHT, HAL_PIXEL_FORMAT_RGBA_8888, 1,
+                new GraphicBuffer(bufferWidth, bufferHeight, HAL_PIXEL_FORMAT_RGBA_8888, 1,
                                   GRALLOC_USAGE_SW_WRITE_RARELY | GRALLOC_USAGE_HW_COMPOSER |
                                           GRALLOC_USAGE_HW_TEXTURE,
                                   "RefreshRateOverlayBuffer");
         const status_t bufferStatus = buffer->initCheck();
         LOG_ALWAYS_FATAL_IF(bufferStatus != OK, "RefreshRateOverlay: Buffer failed to allocate: %d",
                             bufferStatus);
-        uint8_t* pixels;
-        buffer->lock(GRALLOC_USAGE_SW_WRITE_RARELY, reinterpret_cast<void**>(&pixels));
-        // Clear buffer content
-        drawRect(Rect(BUFFER_WIDTH, BUFFER_HEIGHT), half4(0), buffer, pixels);
+
+        sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(bufferWidth, bufferHeight);
+        SkCanvas* canvas = surface->getCanvas();
+        canvas->setMatrix(canvasTransform);
+
         int left = 0;
         if (hundreds != 0) {
-            drawDigit(hundreds, left, color, buffer, pixels);
+            drawDigit(hundreds, left, color, *canvas);
         }
         left += DIGIT_WIDTH + DIGIT_SPACE;
 
         if (tens != 0) {
-            drawDigit(tens, left, color, buffer, pixels);
+            drawDigit(tens, left, color, *canvas);
         }
         left += DIGIT_WIDTH + DIGIT_SPACE;
 
-        drawDigit(ones, left, color, buffer, pixels);
+        drawDigit(ones, left, color, *canvas);
         left += DIGIT_WIDTH + DIGIT_SPACE;
 
         if (showSpinner) {
             switch (i) {
                 case 0:
-                    drawSegment(Segment::Upper, left, color, buffer, pixels);
+                    drawSegment(Segment::Upper, left, color, *canvas);
                     break;
                 case 1:
-                    drawSegment(Segment::UpperRight, left, color, buffer, pixels);
+                    drawSegment(Segment::UpperRight, left, color, *canvas);
                     break;
                 case 2:
-                    drawSegment(Segment::LowerRight, left, color, buffer, pixels);
+                    drawSegment(Segment::LowerRight, left, color, *canvas);
                     break;
                 case 3:
-                    drawSegment(Segment::Buttom, left, color, buffer, pixels);
+                    drawSegment(Segment::Bottom, left, color, *canvas);
                     break;
                 case 4:
-                    drawSegment(Segment::LowerLeft, left, color, buffer, pixels);
+                    drawSegment(Segment::LowerLeft, left, color, *canvas);
                     break;
                 case 5:
-                    drawSegment(Segment::UpperLeft, left, color, buffer, pixels);
+                    drawSegment(Segment::UpperLeft, left, color, *canvas);
                     break;
             }
         }
 
+        void* pixels = nullptr;
+        buffer->lock(GRALLOC_USAGE_SW_WRITE_RARELY, reinterpret_cast<void**>(&pixels));
+        const SkImageInfo& imageInfo = surface->imageInfo();
+        size_t dstRowBytes = buffer->getStride() * imageInfo.bytesPerPixel();
+        canvas->readPixels(imageInfo, pixels, dstRowBytes, 0, 0);
         buffer->unlock();
         buffers.emplace_back(buffer);
     }
@@ -214,7 +218,22 @@
 
 const std::vector<std::shared_ptr<renderengine::ExternalTexture>>&
 RefreshRateOverlay::getOrCreateBuffers(uint32_t fps) {
-    if (mBufferCache.find(fps) == mBufferCache.end()) {
+    ui::Transform::RotationFlags transformHint = mLayer->getTransformHint();
+    // Tell SurfaceFlinger about the pre-rotation on the buffer.
+    const auto transform = [&] {
+        switch (transformHint) {
+            case ui::Transform::ROT_90:
+                return ui::Transform::ROT_270;
+            case ui::Transform::ROT_270:
+                return ui::Transform::ROT_90;
+            default:
+                return ui::Transform::ROT_0;
+        }
+    }();
+    mLayer->setTransform(transform);
+
+    if (mBufferCache.find(transformHint) == mBufferCache.end() ||
+        mBufferCache.at(transformHint).find(fps) == mBufferCache.at(transformHint).end()) {
         // Ensure the range is > 0, so we don't divide by 0.
         const auto rangeLength = std::max(1u, mHighFps - mLowFps);
         // Clip values outside the range [mLowFps, mHighFps]. The current fps may be outside
@@ -222,12 +241,14 @@
         fps = std::max(fps, mLowFps);
         fps = std::min(fps, mHighFps);
         const auto fpsScale = static_cast<float>(fps - mLowFps) / rangeLength;
-        half4 color;
-        color.r = HIGH_FPS_COLOR.r * fpsScale + LOW_FPS_COLOR.r * (1 - fpsScale);
-        color.g = HIGH_FPS_COLOR.g * fpsScale + LOW_FPS_COLOR.g * (1 - fpsScale);
-        color.b = HIGH_FPS_COLOR.b * fpsScale + LOW_FPS_COLOR.b * (1 - fpsScale);
-        color.a = ALPHA;
-        auto buffers = SevenSegmentDrawer::drawNumber(fps, color, mShowSpinner);
+        SkColor4f colorBase = SkColor4f::FromColor(HIGH_FPS_COLOR) * fpsScale;
+        SkColor4f lowFpsColor = SkColor4f::FromColor(LOW_FPS_COLOR) * (1 - fpsScale);
+        colorBase.fR = colorBase.fR + lowFpsColor.fR;
+        colorBase.fG = colorBase.fG + lowFpsColor.fG;
+        colorBase.fB = colorBase.fB + lowFpsColor.fB;
+        colorBase.fA = ALPHA;
+        SkColor color = colorBase.toSkColor();
+        auto buffers = SevenSegmentDrawer::draw(fps, color, transformHint, mShowSpinner);
         std::vector<std::shared_ptr<renderengine::ExternalTexture>> textures;
         std::transform(buffers.begin(), buffers.end(), std::back_inserter(textures),
                        [&](const auto& buffer) -> std::shared_ptr<renderengine::ExternalTexture> {
@@ -237,10 +258,10 @@
                                                                   renderengine::ExternalTexture::
                                                                           Usage::READABLE);
                        });
-        mBufferCache.emplace(fps, textures);
+        mBufferCache[transformHint].emplace(fps, textures);
     }
 
-    return mBufferCache[fps];
+    return mBufferCache[transformHint][fps];
 }
 
 void RefreshRateOverlay::setViewport(ui::Size viewport) {
diff --git a/services/surfaceflinger/RefreshRateOverlay.h b/services/surfaceflinger/RefreshRateOverlay.h
index f9baa89..fd1e2df 100644
--- a/services/surfaceflinger/RefreshRateOverlay.h
+++ b/services/surfaceflinger/RefreshRateOverlay.h
@@ -22,6 +22,8 @@
 #include <ui/Size.h>
 #include <utils/StrongPointer.h>
 
+#include <SkCanvas.h>
+#include <SkColor.h>
 #include <unordered_map>
 
 #include "Fps.h"
@@ -47,20 +49,16 @@
 private:
     class SevenSegmentDrawer {
     public:
-        static std::vector<sp<GraphicBuffer>> drawNumber(int number, const half4& color,
-                                                         bool showSpinner);
+        static std::vector<sp<GraphicBuffer>> draw(int number, SkColor& color,
+                                                   ui::Transform::RotationFlags, bool showSpinner);
         static uint32_t getHeight() { return BUFFER_HEIGHT; }
         static uint32_t getWidth() { return BUFFER_WIDTH; }
 
     private:
-        enum class Segment { Upper, UpperLeft, UpperRight, Middle, LowerLeft, LowerRight, Buttom };
+        enum class Segment { Upper, UpperLeft, UpperRight, Middle, LowerLeft, LowerRight, Bottom };
 
-        static void drawRect(const Rect& r, const half4& color, const sp<GraphicBuffer>& buffer,
-                             uint8_t* pixels);
-        static void drawSegment(Segment segment, int left, const half4& color,
-                                const sp<GraphicBuffer>& buffer, uint8_t* pixels);
-        static void drawDigit(int digit, int left, const half4& color,
-                              const sp<GraphicBuffer>& buffer, uint8_t* pixels);
+        static void drawSegment(Segment segment, int left, SkColor& color, SkCanvas& canvas);
+        static void drawDigit(int digit, int left, SkColor& color, SkCanvas& canvas);
 
         static constexpr uint32_t DIGIT_HEIGHT = 100;
         static constexpr uint32_t DIGIT_WIDTH = 64;
@@ -80,13 +78,15 @@
     sp<IBinder> mIBinder;
     sp<IGraphicBufferProducer> mGbp;
 
-    std::unordered_map<int, std::vector<std::shared_ptr<renderengine::ExternalTexture>>>
+    std::unordered_map<
+            ui::Transform::RotationFlags,
+            std::unordered_map<int, std::vector<std::shared_ptr<renderengine::ExternalTexture>>>>
             mBufferCache;
     std::optional<int> mCurrentFps;
     int mFrame = 0;
     static constexpr float ALPHA = 0.8f;
-    const half3 LOW_FPS_COLOR = half3(1.0f, 0.0f, 0.0f);
-    const half3 HIGH_FPS_COLOR = half3(0.0f, 1.0f, 0.0f);
+    const SkColor LOW_FPS_COLOR = SK_ColorRED;
+    const SkColor HIGH_FPS_COLOR = SK_ColorGREEN;
 
     const bool mShowSpinner;
 
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 5e17828..bc6e6fd 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5655,37 +5655,24 @@
             }
             case 1035: {
                 const int modeId = data.readInt32();
-                mDebugDisplayModeSetByBackdoor = false;
 
-                const auto displayId = [&]() -> std::optional<PhysicalDisplayId> {
-                    uint64_t inputDisplayId = 0;
-                    if (data.readUint64(&inputDisplayId) == NO_ERROR) {
-                        const auto token = getPhysicalDisplayToken(
-                                static_cast<PhysicalDisplayId>(inputDisplayId));
-                        if (!token) {
-                            ALOGE("No display with id: %" PRIu64, inputDisplayId);
-                            return std::nullopt;
-                        }
-
-                        return std::make_optional<PhysicalDisplayId>(inputDisplayId);
+                const auto display = [&]() -> sp<IBinder> {
+                    uint64_t value;
+                    if (data.readUint64(&value) != NO_ERROR) {
+                        return getDefaultDisplayDevice()->getDisplayToken().promote();
                     }
 
-                    return getDefaultDisplayDevice()->getPhysicalId();
+                    if (const auto id = DisplayId::fromValue<PhysicalDisplayId>(value)) {
+                        return getPhysicalDisplayToken(*id);
+                    }
+
+                    ALOGE("Invalid physical display ID");
+                    return nullptr;
                 }();
 
-                if (!displayId) {
-                    ALOGE("No display found");
-                    return NO_ERROR;
-                }
-
-                status_t result = setActiveMode(getPhysicalDisplayToken(*displayId), modeId);
-                if (result != NO_ERROR) {
-                    return result;
-                }
-
-                mDebugDisplayModeSetByBackdoor = true;
-
-                return NO_ERROR;
+                const status_t result = setActiveMode(display, modeId);
+                mDebugDisplayModeSetByBackdoor = result == NO_ERROR;
+                return result;
             }
             case 1036: {
                 if (data.readInt32() > 0) {
@@ -5748,14 +5735,11 @@
                             std::optional<PhysicalDisplayId> inputId = std::nullopt;
                             if (uint64_t inputDisplayId;
                                 data.readUint64(&inputDisplayId) == NO_ERROR) {
-                                const auto token = getPhysicalDisplayToken(
-                                        static_cast<PhysicalDisplayId>(inputDisplayId));
-                                if (!token) {
+                                inputId = DisplayId::fromValue<PhysicalDisplayId>(inputDisplayId);
+                                if (!inputId || getPhysicalDisplayToken(*inputId)) {
                                     ALOGE("No display with id: %" PRIu64, inputDisplayId);
                                     return NAME_NOT_FOUND;
                                 }
-
-                                inputId = std::make_optional<PhysicalDisplayId>(inputDisplayId);
                             }
                             {
                                 Mutex::Autolock lock(mStateLock);
@@ -6013,7 +5997,7 @@
                                captureListener);
 }
 
-status_t SurfaceFlinger::captureDisplay(uint64_t displayIdOrLayerStack,
+status_t SurfaceFlinger::captureDisplay(DisplayId displayId,
                                         const sp<IScreenCaptureListener>& captureListener) {
     ui::LayerStack layerStack;
     wp<const DisplayDevice> displayWeak;
@@ -6021,21 +6005,14 @@
     ui::Dataspace dataspace;
     {
         Mutex::Autolock lock(mStateLock);
-        auto display = getDisplayDeviceLocked(PhysicalDisplayId{displayIdOrLayerStack});
 
-        // Fall back to first display whose layer stack matches.
-        if (!display) {
-            const auto layerStack = static_cast<ui::LayerStack>(displayIdOrLayerStack);
-            display = findDisplay(WithLayerStack(layerStack));
-        }
-
+        const auto display = getDisplayDeviceLocked(displayId);
         if (!display) {
             return NAME_NOT_FOUND;
         }
 
-        layerStack = display->getLayerStack();
         displayWeak = display;
-
+        layerStack = display->getLayerStack();
         size = display->getLayerStackSpaceRect().getSize();
 
         dataspace =
@@ -6120,7 +6097,11 @@
             }
         }
 
-        const auto display = findDisplay(WithLayerStack(parent->getLayerStack()));
+        const auto display =
+                findDisplay([layerStack = parent->getLayerStack()](const auto& display) {
+                    return display.getLayerStack() == layerStack;
+                });
+
         if (!display) {
             return NAME_NOT_FOUND;
         }
@@ -6328,7 +6309,6 @@
 
     const auto display = renderArea.getDisplayDevice();
     std::vector<Layer*> renderedLayers;
-    Region clearRegion = Region::INVALID_REGION;
     bool disableBlurs = false;
     traverseLayers([&](Layer* layer) {
         disableBlurs |= layer->getDrawingState().sidebandStream != nullptr;
@@ -6340,7 +6320,6 @@
                         renderArea.needsFiltering(),
                 renderArea.isSecure(),
                 useProtected,
-                clearRegion,
                 layerStackSpaceRect,
                 clientCompositionDisplay.outputDataspace,
                 true,  /* realContentIsVisible */
@@ -6378,7 +6357,6 @@
                    clientCompositionLayerPointers.begin(),
                    std::pointer_traits<renderengine::LayerSettings*>::pointer_to);
 
-    clientCompositionDisplay.clearRegion = clearRegion;
     // Use an empty fence for the buffer fence, since we just created the buffer so
     // there is no need for synchronization with the GPU.
     base::unique_fd bufferFence;
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 9142978..80f3f9c 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -627,12 +627,10 @@
     sp<IDisplayEventConnection> createDisplayEventConnection(
             ISurfaceComposer::VsyncSource vsyncSource = eVsyncSourceApp,
             ISurfaceComposer::EventRegistrationFlags eventRegistration = {}) override;
-    status_t captureDisplay(const DisplayCaptureArgs& args,
-                            const sp<IScreenCaptureListener>& captureListener) override;
-    status_t captureDisplay(uint64_t displayOrLayerStack,
-                            const sp<IScreenCaptureListener>& captureListener) override;
-    status_t captureLayers(const LayerCaptureArgs& args,
-                           const sp<IScreenCaptureListener>& captureListener) override;
+
+    status_t captureDisplay(const DisplayCaptureArgs&, const sp<IScreenCaptureListener>&) override;
+    status_t captureDisplay(DisplayId, const sp<IScreenCaptureListener>&) override;
+    status_t captureLayers(const LayerCaptureArgs&, const sp<IScreenCaptureListener>&) override;
 
     status_t getDisplayStats(const sp<IBinder>& displayToken, DisplayStatInfo* stats) override;
     status_t getDisplayState(const sp<IBinder>& displayToken, ui::DisplayState*)
diff --git a/services/surfaceflinger/tests/fakehwc/SFFakeHwc_test.cpp b/services/surfaceflinger/tests/fakehwc/SFFakeHwc_test.cpp
index 162711d..a9e935d 100644
--- a/services/surfaceflinger/tests/fakehwc/SFFakeHwc_test.cpp
+++ b/services/surfaceflinger/tests/fakehwc/SFFakeHwc_test.cpp
@@ -279,7 +279,7 @@
     }
 
     bool waitForHotplugEvent(Display displayId, bool connected) {
-        return waitForHotplugEvent(PhysicalDisplayId(displayId), connected);
+        return waitForHotplugEvent(physicalIdFromHwcDisplayId(displayId), connected);
     }
 
     bool waitForHotplugEvent(PhysicalDisplayId displayId, bool connected) {
@@ -305,7 +305,7 @@
     }
 
     bool waitForModeChangedEvent(Display display, int32_t modeId) {
-        PhysicalDisplayId displayId(display);
+        PhysicalDisplayId displayId = physicalIdFromHwcDisplayId(display);
         int waitCount = 20;
         while (waitCount--) {
             while (!mReceivedDisplayEvents.empty()) {
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index 9e704c3..8bd6e62 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -23,7 +23,10 @@
 
 cc_test {
     name: "libsurfaceflinger_unittest",
-    defaults: ["surfaceflinger_defaults"],
+    defaults: [
+        "skia_renderengine_deps",
+        "surfaceflinger_defaults",
+    ],
     test_suites: ["device-tests"],
     sanitize: {
         // Using the address sanitizer not only helps uncover issues in the code
diff --git a/services/surfaceflinger/tests/unittests/CompositionTest.cpp b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
index 560f139..fca3bfc 100644
--- a/services/surfaceflinger/tests/unittests/CompositionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
@@ -77,7 +77,7 @@
 constexpr hal::HWLayerId HWC_LAYER = 5000;
 constexpr Transform DEFAULT_TRANSFORM = static_cast<Transform>(0);
 
-constexpr PhysicalDisplayId DEFAULT_DISPLAY_ID(42);
+constexpr PhysicalDisplayId DEFAULT_DISPLAY_ID = PhysicalDisplayId::fromPort(42u);
 constexpr int DEFAULT_DISPLAY_WIDTH = 1920;
 constexpr int DEFAULT_DISPLAY_HEIGHT = 1024;
 
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index cc24323..60b0f53 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -122,7 +122,7 @@
 
 sp<DisplayDevice> DisplayTransactionTest::injectDefaultInternalDisplay(
         std::function<void(FakeDisplayDeviceInjector&)> injectExtra) {
-    constexpr PhysicalDisplayId DEFAULT_DISPLAY_ID(777);
+    constexpr PhysicalDisplayId DEFAULT_DISPLAY_ID = PhysicalDisplayId::fromPort(255u);
     constexpr int DEFAULT_DISPLAY_WIDTH = 1080;
     constexpr int DEFAULT_DISPLAY_HEIGHT = 1920;
     constexpr HWDisplayId DEFAULT_DISPLAY_HWC_DISPLAY_ID = 0;
diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index 4ff7592..28d0222 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -41,10 +41,13 @@
 
 namespace {
 
-constexpr PhysicalDisplayId INTERNAL_DISPLAY_ID(111);
-constexpr PhysicalDisplayId EXTERNAL_DISPLAY_ID(222);
-constexpr PhysicalDisplayId DISPLAY_ID_64BIT(0xabcd12349876fedcULL);
+constexpr PhysicalDisplayId INTERNAL_DISPLAY_ID = PhysicalDisplayId::fromPort(111u);
+constexpr PhysicalDisplayId EXTERNAL_DISPLAY_ID = PhysicalDisplayId::fromPort(222u);
+constexpr PhysicalDisplayId DISPLAY_ID_64BIT =
+        PhysicalDisplayId::fromEdid(0xffu, 0xffffu, 0xffff'ffffu);
+
 constexpr std::chrono::duration VSYNC_PERIOD(16ms);
+
 class MockVSyncSource : public VSyncSource {
 public:
     const char* getName() const override { return "test"; }
diff --git a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
index 02ec7fc..bb21ad6 100644
--- a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
@@ -118,13 +118,15 @@
     std::shared_ptr<RefreshRateConfigs> mConfigs = std::make_shared<
             RefreshRateConfigs>(DisplayModes{DisplayMode::Builder(0)
                                                      .setId(DisplayModeId(0))
-                                                     .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                                     .setPhysicalDisplayId(
+                                                             PhysicalDisplayId::fromPort(0))
                                                      .setVsyncPeriod(int32_t(LO_FPS_PERIOD))
                                                      .setGroup(0)
                                                      .build(),
                                              DisplayMode::Builder(1)
                                                      .setId(DisplayModeId(1))
-                                                     .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                                     .setPhysicalDisplayId(
+                                                             PhysicalDisplayId::fromPort(0))
                                                      .setVsyncPeriod(int32_t(HI_FPS_PERIOD))
                                                      .setGroup(0)
                                                      .build()},
diff --git a/services/surfaceflinger/tests/unittests/OneShotTimerTest.cpp b/services/surfaceflinger/tests/unittests/OneShotTimerTest.cpp
index 6916764..597e5e7 100644
--- a/services/surfaceflinger/tests/unittests/OneShotTimerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/OneShotTimerTest.cpp
@@ -72,7 +72,8 @@
     mIdleTimer->stop();
 }
 
-TEST_F(OneShotTimerTest, resetTest) {
+// TODO(b/186417847) This test is flaky. Reenable once fixed.
+TEST_F(OneShotTimerTest, DISABLED_resetTest) {
     fake::FakeClock* clock = new fake::FakeClock();
     mIdleTimer = std::make_unique<scheduler::OneShotTimer>("TestTimer", 1ms,
                                                            mResetTimerCallback.getInvocable(),
@@ -94,7 +95,8 @@
     EXPECT_FALSE(mResetTimerCallback.waitForUnexpectedCall().has_value());
 }
 
-TEST_F(OneShotTimerTest, resetBackToBackTest) {
+// TODO(b/186417847) This test is flaky. Reenable once fixed.
+TEST_F(OneShotTimerTest, DISABLED_resetBackToBackTest) {
     fake::FakeClock* clock = new fake::FakeClock();
     mIdleTimer = std::make_unique<scheduler::OneShotTimer>("TestTimer", 1ms,
                                                            mResetTimerCallback.getInvocable(),
@@ -144,7 +146,8 @@
     EXPECT_FALSE(mResetTimerCallback.waitForUnexpectedCall().has_value());
 }
 
-TEST_F(OneShotTimerTest, idleTimerIdlesTest) {
+// TODO(b/186417847) This test is flaky. Reenable once fixed.
+TEST_F(OneShotTimerTest, DISABLED_idleTimerIdlesTest) {
     fake::FakeClock* clock = new fake::FakeClock();
     mIdleTimer = std::make_unique<scheduler::OneShotTimer>("TestTimer", 1ms,
                                                            mResetTimerCallback.getInvocable(),
@@ -169,7 +172,8 @@
     EXPECT_FALSE(mResetTimerCallback.waitForUnexpectedCall().has_value());
 }
 
-TEST_F(OneShotTimerTest, timeoutCallbackExecutionTest) {
+// TODO(b/186417847) This test is flaky. Reenable once fixed.
+TEST_F(OneShotTimerTest, DISABLED_timeoutCallbackExecutionTest) {
     fake::FakeClock* clock = new fake::FakeClock();
     mIdleTimer = std::make_unique<scheduler::OneShotTimer>("TestTimer", 1ms,
                                                            mResetTimerCallback.getInvocable(),
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
index 6870fd4..c04919f 100644
--- a/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
+++ b/services/surfaceflinger/tests/unittests/RefreshRateConfigsTest.cpp
@@ -181,7 +181,7 @@
                                                          int64_t vsyncPeriod, ui::Size resolution) {
     return DisplayMode::Builder(hal::HWConfigId(modeId.value()))
             .setId(modeId)
-            .setPhysicalDisplayId(PhysicalDisplayId(0))
+            .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
             .setVsyncPeriod(int32_t(vsyncPeriod))
             .setGroup(group)
             .setHeight(resolution.height)
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp
index 12b155b..0a8759d 100644
--- a/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp
+++ b/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp
@@ -81,7 +81,7 @@
                                                        int64_t vsyncPeriod) {
     return DisplayMode::Builder(static_cast<hal::HWConfigId>(modeId.value()))
             .setId(modeId)
-            .setPhysicalDisplayId(PhysicalDisplayId(0))
+            .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
             .setVsyncPeriod(static_cast<int32_t>(vsyncPeriod))
             .setGroup(group)
             .build();
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
index 5713c2f..e2b3993 100644
--- a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -34,7 +34,7 @@
 namespace android {
 namespace {
 
-constexpr PhysicalDisplayId PHYSICAL_DISPLAY_ID(999);
+constexpr PhysicalDisplayId PHYSICAL_DISPLAY_ID = PhysicalDisplayId::fromPort(255u);
 
 class SchedulerTest : public testing::Test {
 protected:
@@ -53,13 +53,13 @@
 
     const DisplayModePtr mode60 = DisplayMode::Builder(0)
                                           .setId(DisplayModeId(0))
-                                          .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                          .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
                                           .setVsyncPeriod(Fps(60.f).getPeriodNsecs())
                                           .setGroup(0)
                                           .build();
     const DisplayModePtr mode120 = DisplayMode::Builder(1)
                                            .setId(DisplayModeId(1))
-                                           .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                           .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
                                            .setVsyncPeriod(Fps(120.f).getPeriodNsecs())
                                            .setGroup(0)
                                            .build();
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 393387b..ad284e3 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -209,7 +209,7 @@
                         ISchedulerCallback* callback = nullptr, bool hasMultipleModes = false) {
         DisplayModes modes{DisplayMode::Builder(0)
                                    .setId(DisplayModeId(0))
-                                   .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                   .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
                                    .setVsyncPeriod(16'666'667)
                                    .setGroup(0)
                                    .build()};
@@ -217,7 +217,7 @@
         if (hasMultipleModes) {
             modes.emplace_back(DisplayMode::Builder(1)
                                        .setId(DisplayModeId(1))
-                                       .setPhysicalDisplayId(PhysicalDisplayId(0))
+                                       .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
                                        .setVsyncPeriod(11'111'111)
                                        .setGroup(0)
                                        .build());
@@ -643,7 +643,7 @@
             DisplayModePtr activeMode =
                     DisplayMode::Builder(FakeHwcDisplayInjector::DEFAULT_ACTIVE_CONFIG)
                             .setId(mActiveModeId)
-                            .setPhysicalDisplayId(PhysicalDisplayId(0))
+                            .setPhysicalDisplayId(PhysicalDisplayId::fromPort(0))
                             .setWidth(FakeHwcDisplayInjector::DEFAULT_WIDTH)
                             .setHeight(FakeHwcDisplayInjector::DEFAULT_HEIGHT)
                             .setVsyncPeriod(FakeHwcDisplayInjector::DEFAULT_VSYNC_PERIOD)
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockComposer.cpp b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockComposer.cpp
index 7de1872..20d41e6 100644
--- a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockComposer.cpp
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockComposer.cpp
@@ -18,6 +18,7 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wconversion"
 
+#undef LOG_TAG
 #define LOG_TAG "MockComposer"
 #include "mock/DisplayHardware/MockComposer.h"
 
diff --git a/vulkan/libvulkan/api_gen.cpp b/vulkan/libvulkan/api_gen.cpp
index 26052fb..33401d2 100644
--- a/vulkan/libvulkan/api_gen.cpp
+++ b/vulkan/libvulkan/api_gen.cpp
@@ -560,6 +560,7 @@
     }
 
     static const char* const known_non_device_names[] = {
+        "vkAcquireDrmDisplayEXT",
         "vkCreateAndroidSurfaceKHR",
         "vkCreateDebugReportCallbackEXT",
         "vkCreateDebugUtilsMessengerEXT",
@@ -581,6 +582,7 @@
         "vkEnumeratePhysicalDevices",
         "vkGetDisplayModeProperties2KHR",
         "vkGetDisplayPlaneCapabilities2KHR",
+        "vkGetDrmDisplayEXT",
         "vkGetInstanceProcAddr",
         "vkGetPhysicalDeviceCalibrateableTimeDomainsEXT",
         "vkGetPhysicalDeviceDisplayPlaneProperties2KHR",
@@ -624,6 +626,8 @@
         "vkGetPhysicalDeviceSurfacePresentModesKHR",
         "vkGetPhysicalDeviceSurfaceSupportKHR",
         "vkGetPhysicalDeviceToolPropertiesEXT",
+        "vkGetPhysicalDeviceVideoCapabilitiesKHR",
+        "vkGetPhysicalDeviceVideoFormatPropertiesKHR",
         "vkSubmitDebugUtilsMessageEXT",
     };
     // clang-format on
diff --git a/vulkan/scripts/generator_common.py b/vulkan/scripts/generator_common.py
index 72fd4fb..4176509 100644
--- a/vulkan/scripts/generator_common.py
+++ b/vulkan/scripts/generator_common.py
@@ -33,6 +33,7 @@
     'VK_EXT_metal_surface',
     'VK_FUCHSIA_imagepipe_surface',
     'VK_GGP_stream_descriptor_surface',
+    'VK_HUAWEI_subpass_shading',
     'VK_KHR_display',
     'VK_KHR_display_swapchain',
     'VK_KHR_external_fence_win32',
@@ -47,11 +48,13 @@
     'VK_MVK_ios_surface',
     'VK_MVK_macos_surface',
     'VK_NN_vi_surface',
+    'VK_NV_acquire_winrt_display',
     'VK_NV_cooperative_matrix',
     'VK_NV_coverage_reduction_mode',
     'VK_NV_external_memory_win32',
     'VK_NV_win32_keyed_mutex',
     'VK_NVX_image_view_handle',
+    'VK_QNX_screen_surface',
 ]
 
 # Extensions having functions exported by the loader.