Add new SF backdoor option: hdr/sdr ratio overlay

 - follow how RefreshRateOverlay did in general.
 - 1043 as new opcode to enable hdr/sdr ratio overlay.
 - decouple SevenSegmentDrawer and SurfaceControlHandle helper classes
   from RefreshRateOverlay.
 - add corresponding SF backdoor test for validation.
 - for non-HDR-supported device, we don't reject them to use SF backdoor
   but 1.00 will be always shown on the screen if enabling.

Test: adb shell call service call SurfaceFlinger 1043 1; atest
SurfaceFlinger_test
Bug: 277957056

Change-Id: Ifce2d435f127b53ab9d01aba4e24ffd4fdb010a7
diff --git a/services/surfaceflinger/tests/HdrSdrRatioOverlay_test.cpp b/services/surfaceflinger/tests/HdrSdrRatioOverlay_test.cpp
new file mode 100644
index 0000000..77a8f9c
--- /dev/null
+++ b/services/surfaceflinger/tests/HdrSdrRatioOverlay_test.cpp
@@ -0,0 +1,89 @@
+/**
+ * Copyright (C) 2023 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 <thread>
+
+#include <gtest/gtest.h>
+
+#include <gui/SurfaceComposerClient.h>
+#include <private/gui/ComposerService.h>
+#include <chrono>
+
+using ::std::literals::chrono_literals::operator""s;
+
+static constexpr int kHdrSdrRatioOverlayCode = 1043;
+static constexpr int kHdrSdrRatioOverlayEnable = 1;
+static constexpr int kHdrSdrRatioOverlayDisable = 0;
+static constexpr int kHdrSdrRatioOverlayQuery = 2;
+
+// These values must match the ones we used for developer options in
+// com.android.settings.development.ShowHdrSdrRatioPreferenceController
+static_assert(kHdrSdrRatioOverlayCode == 1043);
+static_assert(kHdrSdrRatioOverlayEnable == 1);
+static_assert(kHdrSdrRatioOverlayDisable == 0);
+static_assert(kHdrSdrRatioOverlayQuery == 2);
+
+namespace android {
+
+namespace {
+void sendCommandToSf(int command, Parcel& reply) {
+    sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+    Parcel request;
+    request.writeInterfaceToken(String16("android.ui.ISurfaceComposer"));
+    request.writeInt32(command);
+    ASSERT_EQ(NO_ERROR,
+              IInterface::asBinder(sf)->transact(kHdrSdrRatioOverlayCode, request, &reply));
+}
+
+bool isOverlayEnabled() {
+    Parcel reply;
+    sendCommandToSf(kHdrSdrRatioOverlayQuery, reply);
+    return reply.readBool();
+}
+
+void waitForOverlay(bool enabled) {
+    static constexpr auto kTimeout = std::chrono::nanoseconds(1s);
+    static constexpr auto kIterations = 10;
+    for (int i = 0; i < kIterations; i++) {
+        if (enabled == isOverlayEnabled()) {
+            return;
+        }
+        std::this_thread::sleep_for(kTimeout / kIterations);
+    }
+}
+
+void toggleOverlay(bool enabled) {
+    if (enabled == isOverlayEnabled()) {
+        return;
+    }
+
+    Parcel reply;
+    const auto command = enabled ? kHdrSdrRatioOverlayEnable : kHdrSdrRatioOverlayDisable;
+    sendCommandToSf(command, reply);
+    waitForOverlay(enabled);
+    ASSERT_EQ(enabled, isOverlayEnabled());
+}
+
+} // namespace
+
+TEST(HdrSdrRatioOverlayTest, enableAndDisableOverlay) {
+    toggleOverlay(true);
+    toggleOverlay(false);
+
+    toggleOverlay(true);
+    toggleOverlay(false);
+}
+
+} // namespace android