diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index 53a3611..159c2a4 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -50,6 +50,7 @@
     "fakehwc",
     "hwc2",
     "unittests",
+    "utils",
     "vsync",
     "waitforvsync",
 ]
diff --git a/services/surfaceflinger/tests/Transaction_test.cpp b/services/surfaceflinger/tests/Transaction_test.cpp
index b1fde22..57e5c51 100644
--- a/services/surfaceflinger/tests/Transaction_test.cpp
+++ b/services/surfaceflinger/tests/Transaction_test.cpp
@@ -20,7 +20,6 @@
 #include <functional>
 #include <limits>
 #include <ostream>
-#include <thread>
 
 #include <gtest/gtest.h>
 
@@ -37,10 +36,7 @@
 #include <private/android_filesystem_config.h>
 #include <private/gui/ComposerService.h>
 
-#include <ui/ColorSpace.h>
 #include <ui/DisplayInfo.h>
-#include <ui/Rect.h>
-#include <utils/String8.h>
 
 #include <math.h>
 #include <math/vec3.h>
@@ -48,293 +44,14 @@
 #include <unistd.h>
 
 #include "BufferGenerator.h"
+#include "utils/CallbackUtils.h"
+#include "utils/ColorUtils.h"
+#include "utils/ScreenshotUtils.h"
+#include "utils/TransactionUtils.h"
 
 namespace android {
 
-namespace {
-
-struct Color {
-    uint8_t r;
-    uint8_t g;
-    uint8_t b;
-    uint8_t a;
-
-    static const Color RED;
-    static const Color GREEN;
-    static const Color BLUE;
-    static const Color WHITE;
-    static const Color BLACK;
-    static const Color TRANSPARENT;
-};
-
-const Color Color::RED{255, 0, 0, 255};
-const Color Color::GREEN{0, 255, 0, 255};
-const Color Color::BLUE{0, 0, 255, 255};
-const Color Color::WHITE{255, 255, 255, 255};
-const Color Color::BLACK{0, 0, 0, 255};
-const Color Color::TRANSPARENT{0, 0, 0, 0};
-
 using android::hardware::graphics::common::V1_1::BufferUsage;
-using namespace std::chrono_literals;
-
-std::ostream& operator<<(std::ostream& os, const Color& color) {
-    os << int(color.r) << ", " << int(color.g) << ", " << int(color.b) << ", " << int(color.a);
-    return os;
-}
-
-// Fill a region with the specified color.
-void fillANativeWindowBufferColor(const ANativeWindow_Buffer& buffer, const Rect& rect,
-                                  const Color& color) {
-    Rect r(0, 0, buffer.width, buffer.height);
-    if (!r.intersect(rect, &r)) {
-        return;
-    }
-
-    int32_t width = r.right - r.left;
-    int32_t height = r.bottom - r.top;
-
-    for (int32_t row = 0; row < height; row++) {
-        uint8_t* dst =
-                static_cast<uint8_t*>(buffer.bits) + (buffer.stride * (r.top + row) + r.left) * 4;
-        for (int32_t column = 0; column < width; column++) {
-            dst[0] = color.r;
-            dst[1] = color.g;
-            dst[2] = color.b;
-            dst[3] = color.a;
-            dst += 4;
-        }
-    }
-}
-
-// Fill a region with the specified color.
-void fillGraphicBufferColor(const sp<GraphicBuffer>& buffer, const Rect& rect, const Color& color) {
-    Rect r(0, 0, buffer->width, buffer->height);
-    if (!r.intersect(rect, &r)) {
-        return;
-    }
-
-    int32_t width = r.right - r.left;
-    int32_t height = r.bottom - r.top;
-
-    uint8_t* pixels;
-    buffer->lock(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
-                 reinterpret_cast<void**>(&pixels));
-
-    for (int32_t row = 0; row < height; row++) {
-        uint8_t* dst = pixels + (buffer->getStride() * (r.top + row) + r.left) * 4;
-        for (int32_t column = 0; column < width; column++) {
-            dst[0] = color.r;
-            dst[1] = color.g;
-            dst[2] = color.b;
-            dst[3] = color.a;
-            dst += 4;
-        }
-    }
-    buffer->unlock();
-}
-
-// Check if a region has the specified color.
-void expectBufferColor(const sp<GraphicBuffer>& outBuffer, uint8_t* pixels, const Rect& rect,
-                       const Color& color, uint8_t tolerance) {
-    int32_t x = rect.left;
-    int32_t y = rect.top;
-    int32_t width = rect.right - rect.left;
-    int32_t height = rect.bottom - rect.top;
-
-    int32_t bufferWidth = int32_t(outBuffer->getWidth());
-    int32_t bufferHeight = int32_t(outBuffer->getHeight());
-    if (x + width > bufferWidth) {
-        x = std::min(x, bufferWidth);
-        width = bufferWidth - x;
-    }
-    if (y + height > bufferHeight) {
-        y = std::min(y, bufferHeight);
-        height = bufferHeight - y;
-    }
-
-    auto colorCompare = [tolerance](uint8_t a, uint8_t b) {
-        uint8_t tmp = a >= b ? a - b : b - a;
-        return tmp <= tolerance;
-    };
-    for (int32_t j = 0; j < height; j++) {
-        const uint8_t* src = pixels + (outBuffer->getStride() * (y + j) + x) * 4;
-        for (int32_t i = 0; i < width; i++) {
-            const uint8_t expected[4] = {color.r, color.g, color.b, color.a};
-            EXPECT_TRUE(std::equal(src, src + 4, expected, colorCompare))
-                    << "pixel @ (" << x + i << ", " << y + j << "): "
-                    << "expected (" << color << "), "
-                    << "got (" << Color{src[0], src[1], src[2], src[3]} << ")";
-            src += 4;
-        }
-    }
-}
-
-} // anonymous namespace
-
-using Transaction = SurfaceComposerClient::Transaction;
-
-// Fill an RGBA_8888 formatted surface with a single color.
-static void fillSurfaceRGBA8(const sp<SurfaceControl>& sc, uint8_t r, uint8_t g, uint8_t b,
-                             bool unlock = true) {
-    ANativeWindow_Buffer outBuffer;
-    sp<Surface> s = sc->getSurface();
-    ASSERT_TRUE(s != nullptr);
-    ASSERT_EQ(NO_ERROR, s->lock(&outBuffer, nullptr));
-    uint8_t* img = reinterpret_cast<uint8_t*>(outBuffer.bits);
-    for (int y = 0; y < outBuffer.height; y++) {
-        for (int x = 0; x < outBuffer.width; x++) {
-            uint8_t* pixel = img + (4 * (y * outBuffer.stride + x));
-            pixel[0] = r;
-            pixel[1] = g;
-            pixel[2] = b;
-            pixel[3] = 255;
-        }
-    }
-    if (unlock) {
-        ASSERT_EQ(NO_ERROR, s->unlockAndPost());
-    }
-}
-
-// A ScreenCapture is a screenshot from SurfaceFlinger that can be used to check
-// individual pixel values for testing purposes.
-class ScreenCapture : public RefBase {
-public:
-    static void captureScreen(std::unique_ptr<ScreenCapture>* sc) {
-        captureScreen(sc, SurfaceComposerClient::getInternalDisplayToken());
-    }
-
-    static void captureScreen(std::unique_ptr<ScreenCapture>* sc, sp<IBinder> displayToken) {
-        const auto sf = ComposerService::getComposerService();
-        SurfaceComposerClient::Transaction().apply(true);
-
-        sp<GraphicBuffer> outBuffer;
-        ASSERT_EQ(NO_ERROR, sf->captureScreen(displayToken, &outBuffer, Rect(), 0, 0, false));
-        *sc = std::make_unique<ScreenCapture>(outBuffer);
-    }
-
-    static void captureLayers(std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
-                              Rect crop = Rect::EMPTY_RECT, float frameScale = 1.0) {
-        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
-        SurfaceComposerClient::Transaction().apply(true);
-
-        sp<GraphicBuffer> outBuffer;
-        ASSERT_EQ(NO_ERROR, sf->captureLayers(parentHandle, &outBuffer, crop, frameScale));
-        *sc = std::make_unique<ScreenCapture>(outBuffer);
-    }
-
-    static void captureChildLayers(std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
-                                   Rect crop = Rect::EMPTY_RECT, float frameScale = 1.0) {
-        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
-        SurfaceComposerClient::Transaction().apply(true);
-
-        sp<GraphicBuffer> outBuffer;
-        ASSERT_EQ(NO_ERROR, sf->captureLayers(parentHandle, &outBuffer, crop, frameScale, true));
-        *sc = std::make_unique<ScreenCapture>(outBuffer);
-    }
-
-    static void captureChildLayersExcluding(
-            std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
-            std::unordered_set<sp<IBinder>, ISurfaceComposer::SpHash<IBinder>> excludeLayers) {
-        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
-        SurfaceComposerClient::Transaction().apply(true);
-
-        sp<GraphicBuffer> outBuffer;
-        ASSERT_EQ(NO_ERROR,
-                  sf->captureLayers(parentHandle, &outBuffer, ui::Dataspace::V0_SRGB,
-                                    ui::PixelFormat::RGBA_8888, Rect::EMPTY_RECT, excludeLayers,
-                                    1.0f, true));
-        *sc = std::make_unique<ScreenCapture>(outBuffer);
-    }
-
-    void expectColor(const Rect& rect, const Color& color, uint8_t tolerance = 0) {
-        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
-        expectBufferColor(mOutBuffer, mPixels, rect, color, tolerance);
-    }
-
-    void expectBorder(const Rect& rect, const Color& color, uint8_t tolerance = 0) {
-        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
-        const bool leftBorder = rect.left > 0;
-        const bool topBorder = rect.top > 0;
-        const bool rightBorder = rect.right < int32_t(mOutBuffer->getWidth());
-        const bool bottomBorder = rect.bottom < int32_t(mOutBuffer->getHeight());
-
-        if (topBorder) {
-            Rect top(rect.left, rect.top - 1, rect.right, rect.top);
-            if (leftBorder) {
-                top.left -= 1;
-            }
-            if (rightBorder) {
-                top.right += 1;
-            }
-            expectColor(top, color, tolerance);
-        }
-        if (leftBorder) {
-            Rect left(rect.left - 1, rect.top, rect.left, rect.bottom);
-            expectColor(left, color, tolerance);
-        }
-        if (rightBorder) {
-            Rect right(rect.right, rect.top, rect.right + 1, rect.bottom);
-            expectColor(right, color, tolerance);
-        }
-        if (bottomBorder) {
-            Rect bottom(rect.left, rect.bottom, rect.right, rect.bottom + 1);
-            if (leftBorder) {
-                bottom.left -= 1;
-            }
-            if (rightBorder) {
-                bottom.right += 1;
-            }
-            expectColor(bottom, color, tolerance);
-        }
-    }
-
-    void expectQuadrant(const Rect& rect, const Color& topLeft, const Color& topRight,
-                        const Color& bottomLeft, const Color& bottomRight, bool filtered = false,
-                        uint8_t tolerance = 0) {
-        ASSERT_TRUE((rect.right - rect.left) % 2 == 0 && (rect.bottom - rect.top) % 2 == 0);
-
-        const int32_t centerX = rect.left + (rect.right - rect.left) / 2;
-        const int32_t centerY = rect.top + (rect.bottom - rect.top) / 2;
-        // avoid checking borders due to unspecified filtering behavior
-        const int32_t offsetX = filtered ? 2 : 0;
-        const int32_t offsetY = filtered ? 2 : 0;
-        expectColor(Rect(rect.left, rect.top, centerX - offsetX, centerY - offsetY), topLeft,
-                    tolerance);
-        expectColor(Rect(centerX + offsetX, rect.top, rect.right, centerY - offsetY), topRight,
-                    tolerance);
-        expectColor(Rect(rect.left, centerY + offsetY, centerX - offsetX, rect.bottom), bottomLeft,
-                    tolerance);
-        expectColor(Rect(centerX + offsetX, centerY + offsetY, rect.right, rect.bottom),
-                    bottomRight, tolerance);
-    }
-
-    void checkPixel(uint32_t x, uint32_t y, uint8_t r, uint8_t g, uint8_t b) {
-        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
-        const uint8_t* pixel = mPixels + (4 * (y * mOutBuffer->getStride() + x));
-        if (r != pixel[0] || g != pixel[1] || b != pixel[2]) {
-            String8 err(String8::format("pixel @ (%3d, %3d): "
-                                        "expected [%3d, %3d, %3d], got [%3d, %3d, %3d]",
-                                        x, y, r, g, b, pixel[0], pixel[1], pixel[2]));
-            EXPECT_EQ(String8(), err) << err.string();
-        }
-    }
-
-    void expectFGColor(uint32_t x, uint32_t y) { checkPixel(x, y, 195, 63, 63); }
-
-    void expectBGColor(uint32_t x, uint32_t y) { checkPixel(x, y, 63, 63, 195); }
-
-    void expectChildColor(uint32_t x, uint32_t y) { checkPixel(x, y, 200, 200, 200); }
-
-    explicit ScreenCapture(const sp<GraphicBuffer>& outBuffer) : mOutBuffer(outBuffer) {
-        mOutBuffer->lock(GRALLOC_USAGE_SW_READ_OFTEN, reinterpret_cast<void**>(&mPixels));
-    }
-
-    ~ScreenCapture() { mOutBuffer->unlock(); }
-
-private:
-    sp<GraphicBuffer> mOutBuffer;
-    uint8_t* mPixels = nullptr;
-};
 
 class LayerTransactionTest : public ::testing::Test {
 protected:
@@ -583,7 +300,6 @@
 
     friend class LayerRenderPathTestHarness;
 };
-enum class RenderPath { SCREENSHOT, VIRTUAL_DISPLAY };
 
 class LayerRenderPathTestHarness {
 public:
@@ -693,13 +409,6 @@
     LayerRenderPathTestHarness mRenderPathHarness;
 };
 
-// Environment for starting up binder threads. This is required for testing
-// virtual displays, as BufferQueue parameters may be queried over binder.
-class BinderEnvironment : public ::testing::Environment {
-public:
-    void SetUp() override { ProcessState::self()->startThreadPool(); }
-};
-
 ::testing::Environment* const binderEnv =
         ::testing::AddGlobalTestEnvironment(new BinderEnvironment());
 
@@ -1338,19 +1047,6 @@
               composer->captureScreen(mDisplay, &outBuffer, Rect(), 0, 0, false));
 }
 
-/** RAII Wrapper around get/seteuid */
-class UIDFaker {
-    uid_t oldId;
-public:
-    UIDFaker(uid_t uid) {
-        oldId = geteuid();
-        seteuid(uid);
-    }
-    ~UIDFaker() {
-        seteuid(oldId);
-    }
-};
-
 TEST_F(LayerTransactionTest, SetFlagsSecureEUidSystem) {
     sp<SurfaceControl> layer;
     ASSERT_NO_FATAL_FAILURE(layer = createLayer("test", 32, 32));
@@ -2934,47 +2630,6 @@
     }
 }
 
-class ColorTransformHelper {
-public:
-    static void DegammaColorSingle(half& s) {
-        if (s <= 0.03928f)
-            s = s / 12.92f;
-        else
-            s = pow((s + 0.055f) / 1.055f, 2.4f);
-    }
-
-    static void DegammaColor(half3& color) {
-        DegammaColorSingle(color.r);
-        DegammaColorSingle(color.g);
-        DegammaColorSingle(color.b);
-    }
-
-    static void GammaColorSingle(half& s) {
-        if (s <= 0.0031308f) {
-            s = s * 12.92f;
-        } else {
-            s = 1.055f * pow(s, (1.0f / 2.4f)) - 0.055f;
-        }
-    }
-
-    static void GammaColor(half3& color) {
-        GammaColorSingle(color.r);
-        GammaColorSingle(color.g);
-        GammaColorSingle(color.b);
-    }
-
-    static void applyMatrix(half3& color, const mat3& mat) {
-        half3 ret = half3(0);
-
-        for (int i = 0; i < 3; i++) {
-            for (int j = 0; j < 3; j++) {
-                ret[i] = ret[i] + color[j] * mat[j][i];
-            }
-        }
-        color = ret;
-    }
-};
-
 TEST_P(LayerRenderTypeTransactionTest, SetColorTransformBasic) {
     sp<SurfaceControl> colorLayer;
     ASSERT_NO_FATAL_FAILURE(colorLayer =
@@ -3138,173 +2793,6 @@
     }
 }
 
-struct CallbackData {
-    CallbackData() = default;
-    CallbackData(nsecs_t time, const sp<Fence>& fence,
-                 const std::vector<SurfaceControlStats>& stats)
-          : latchTime(time), presentFence(fence), surfaceControlStats(stats) {}
-
-    nsecs_t latchTime;
-    sp<Fence> presentFence;
-    std::vector<SurfaceControlStats> surfaceControlStats;
-};
-
-class ExpectedResult {
-public:
-    enum Transaction {
-        NOT_PRESENTED = 0,
-        PRESENTED,
-    };
-
-    enum Buffer {
-        NOT_ACQUIRED = 0,
-        ACQUIRED,
-    };
-
-    enum PreviousBuffer {
-        NOT_RELEASED = 0,
-        RELEASED,
-        UNKNOWN,
-    };
-
-    void reset() {
-        mTransactionResult = ExpectedResult::Transaction::NOT_PRESENTED;
-        mExpectedSurfaceResults.clear();
-    }
-
-    void addSurface(ExpectedResult::Transaction transactionResult, const sp<SurfaceControl>& layer,
-                    ExpectedResult::Buffer bufferResult = ACQUIRED,
-                    ExpectedResult::PreviousBuffer previousBufferResult = NOT_RELEASED) {
-        mTransactionResult = transactionResult;
-        mExpectedSurfaceResults.emplace(std::piecewise_construct, std::forward_as_tuple(layer),
-                                        std::forward_as_tuple(bufferResult, previousBufferResult));
-    }
-
-    void addSurfaces(ExpectedResult::Transaction transactionResult,
-                     const std::vector<sp<SurfaceControl>>& layers,
-                     ExpectedResult::Buffer bufferResult = ACQUIRED,
-                     ExpectedResult::PreviousBuffer previousBufferResult = NOT_RELEASED) {
-        for (const auto& layer : layers) {
-            addSurface(transactionResult, layer, bufferResult, previousBufferResult);
-        }
-    }
-
-    void addExpectedPresentTime(nsecs_t expectedPresentTime) {
-        mExpectedPresentTime = expectedPresentTime;
-    }
-
-    void verifyCallbackData(const CallbackData& callbackData) const {
-        const auto& [latchTime, presentFence, surfaceControlStats] = callbackData;
-        if (mTransactionResult == ExpectedResult::Transaction::PRESENTED) {
-            ASSERT_GE(latchTime, 0) << "bad latch time";
-            ASSERT_NE(presentFence, nullptr);
-            if (mExpectedPresentTime >= 0) {
-                ASSERT_EQ(presentFence->wait(3000), NO_ERROR);
-                ASSERT_GE(presentFence->getSignalTime(), mExpectedPresentTime - nsecs_t(5 * 1e6));
-                // if the panel is running at 30 hz, at the worst case, our expected time just
-                // misses vsync and we have to wait another 33.3ms
-                ASSERT_LE(presentFence->getSignalTime(),
-                          mExpectedPresentTime + nsecs_t(66.666666 * 1e6));
-            }
-        } else {
-            ASSERT_EQ(presentFence, nullptr) << "transaction shouldn't have been presented";
-            ASSERT_EQ(latchTime, -1) << "unpresented transactions shouldn't be latched";
-        }
-
-        ASSERT_EQ(surfaceControlStats.size(), mExpectedSurfaceResults.size())
-                << "wrong number of surfaces";
-
-        for (const auto& stats : surfaceControlStats) {
-            ASSERT_NE(stats.surfaceControl, nullptr) << "returned null surface control";
-
-            const auto& expectedSurfaceResult = mExpectedSurfaceResults.find(stats.surfaceControl);
-            ASSERT_NE(expectedSurfaceResult, mExpectedSurfaceResults.end())
-                    << "unexpected surface control";
-            expectedSurfaceResult->second.verifySurfaceControlStats(stats, latchTime);
-        }
-    }
-
-private:
-    class ExpectedSurfaceResult {
-    public:
-        ExpectedSurfaceResult(ExpectedResult::Buffer bufferResult,
-                              ExpectedResult::PreviousBuffer previousBufferResult)
-              : mBufferResult(bufferResult), mPreviousBufferResult(previousBufferResult) {}
-
-        void verifySurfaceControlStats(const SurfaceControlStats& surfaceControlStats,
-                                       nsecs_t latchTime) const {
-            const auto& [surfaceControl, acquireTime, previousReleaseFence] = surfaceControlStats;
-
-            ASSERT_EQ(acquireTime > 0, mBufferResult == ExpectedResult::Buffer::ACQUIRED)
-                    << "bad acquire time";
-            ASSERT_LE(acquireTime, latchTime) << "acquire time should be <= latch time";
-
-            if (mPreviousBufferResult == ExpectedResult::PreviousBuffer::RELEASED) {
-                ASSERT_NE(previousReleaseFence, nullptr)
-                        << "failed to set release prev buffer fence";
-            } else if (mPreviousBufferResult == ExpectedResult::PreviousBuffer::NOT_RELEASED) {
-                ASSERT_EQ(previousReleaseFence, nullptr)
-                        << "should not have set released prev buffer fence";
-            }
-        }
-
-    private:
-        ExpectedResult::Buffer mBufferResult;
-        ExpectedResult::PreviousBuffer mPreviousBufferResult;
-    };
-
-    struct SCHash {
-        std::size_t operator()(const sp<SurfaceControl>& sc) const {
-            return std::hash<IBinder*>{}(sc->getHandle().get());
-        }
-    };
-    ExpectedResult::Transaction mTransactionResult = ExpectedResult::Transaction::NOT_PRESENTED;
-    nsecs_t mExpectedPresentTime = -1;
-    std::unordered_map<sp<SurfaceControl>, ExpectedSurfaceResult, SCHash> mExpectedSurfaceResults;
-};
-
-class CallbackHelper {
-public:
-    static void function(void* callbackContext, nsecs_t latchTime, const sp<Fence>& presentFence,
-                         const std::vector<SurfaceControlStats>& stats) {
-        if (!callbackContext) {
-            ALOGE("failed to get callback context");
-        }
-        CallbackHelper* helper = static_cast<CallbackHelper*>(callbackContext);
-        std::lock_guard lock(helper->mMutex);
-        helper->mCallbackDataQueue.emplace(latchTime, presentFence, stats);
-        helper->mConditionVariable.notify_all();
-    }
-
-    void getCallbackData(CallbackData* outData) {
-        std::unique_lock lock(mMutex);
-
-        if (mCallbackDataQueue.empty()) {
-            ASSERT_NE(mConditionVariable.wait_for(lock, std::chrono::seconds(3)),
-                      std::cv_status::timeout)
-                    << "did not receive callback";
-        }
-
-        *outData = std::move(mCallbackDataQueue.front());
-        mCallbackDataQueue.pop();
-    }
-
-    void verifyFinalState() {
-        // Wait to see if there are extra callbacks
-        std::this_thread::sleep_for(500ms);
-
-        std::lock_guard lock(mMutex);
-        EXPECT_EQ(mCallbackDataQueue.size(), 0) << "extra callbacks received";
-        mCallbackDataQueue = {};
-    }
-
-    void* getContext() { return static_cast<void*>(this); }
-
-    std::mutex mMutex;
-    std::condition_variable mConditionVariable;
-    std::queue<CallbackData> mCallbackDataQueue;
-};
-
 class LayerCallbackTest : public LayerTransactionTest {
 public:
     virtual sp<SurfaceControl> createBufferStateLayer() {
diff --git a/services/surfaceflinger/tests/utils/CallbackUtils.h b/services/surfaceflinger/tests/utils/CallbackUtils.h
new file mode 100644
index 0000000..51ae8c4
--- /dev/null
+++ b/services/surfaceflinger/tests/utils/CallbackUtils.h
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 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.
+ */
+#pragma once
+
+#include <gtest/gtest.h>
+#include <gui/SurfaceComposerClient.h>
+#include <gui/SurfaceControl.h>
+#include <ui/Fence.h>
+#include <utils/Timers.h>
+#include <thread>
+
+namespace android {
+
+namespace {
+
+struct CallbackData {
+    CallbackData() = default;
+    CallbackData(nsecs_t time, const sp<Fence>& fence,
+                 const std::vector<SurfaceControlStats>& stats)
+          : latchTime(time), presentFence(fence), surfaceControlStats(stats) {}
+
+    nsecs_t latchTime;
+    sp<Fence> presentFence;
+    std::vector<SurfaceControlStats> surfaceControlStats;
+};
+
+class ExpectedResult {
+public:
+    enum Transaction {
+        NOT_PRESENTED = 0,
+        PRESENTED,
+    };
+
+    enum Buffer {
+        NOT_ACQUIRED = 0,
+        ACQUIRED,
+    };
+
+    enum PreviousBuffer {
+        NOT_RELEASED = 0,
+        RELEASED,
+        UNKNOWN,
+    };
+
+    void reset() {
+        mTransactionResult = ExpectedResult::Transaction::NOT_PRESENTED;
+        mExpectedSurfaceResults.clear();
+    }
+
+    void addSurface(ExpectedResult::Transaction transactionResult, const sp<SurfaceControl>& layer,
+                    ExpectedResult::Buffer bufferResult = ACQUIRED,
+                    ExpectedResult::PreviousBuffer previousBufferResult = NOT_RELEASED) {
+        mTransactionResult = transactionResult;
+        mExpectedSurfaceResults.emplace(std::piecewise_construct, std::forward_as_tuple(layer),
+                                        std::forward_as_tuple(bufferResult, previousBufferResult));
+    }
+
+    void addSurfaces(ExpectedResult::Transaction transactionResult,
+                     const std::vector<sp<SurfaceControl>>& layers,
+                     ExpectedResult::Buffer bufferResult = ACQUIRED,
+                     ExpectedResult::PreviousBuffer previousBufferResult = NOT_RELEASED) {
+        for (const auto& layer : layers) {
+            addSurface(transactionResult, layer, bufferResult, previousBufferResult);
+        }
+    }
+
+    void addExpectedPresentTime(nsecs_t expectedPresentTime) {
+        mExpectedPresentTime = expectedPresentTime;
+    }
+
+    void verifyCallbackData(const CallbackData& callbackData) const {
+        const auto& [latchTime, presentFence, surfaceControlStats] = callbackData;
+        if (mTransactionResult == ExpectedResult::Transaction::PRESENTED) {
+            ASSERT_GE(latchTime, 0) << "bad latch time";
+            ASSERT_NE(presentFence, nullptr);
+            if (mExpectedPresentTime >= 0) {
+                ASSERT_EQ(presentFence->wait(3000), NO_ERROR);
+                ASSERT_GE(presentFence->getSignalTime(), mExpectedPresentTime - nsecs_t(5 * 1e6));
+                // if the panel is running at 30 hz, at the worst case, our expected time just
+                // misses vsync and we have to wait another 33.3ms
+                ASSERT_LE(presentFence->getSignalTime(),
+                          mExpectedPresentTime + nsecs_t(66.666666 * 1e6));
+            }
+        } else {
+            ASSERT_EQ(presentFence, nullptr) << "transaction shouldn't have been presented";
+            ASSERT_EQ(latchTime, -1) << "unpresented transactions shouldn't be latched";
+        }
+
+        ASSERT_EQ(surfaceControlStats.size(), mExpectedSurfaceResults.size())
+                << "wrong number of surfaces";
+
+        for (const auto& stats : surfaceControlStats) {
+            ASSERT_NE(stats.surfaceControl, nullptr) << "returned null surface control";
+
+            const auto& expectedSurfaceResult = mExpectedSurfaceResults.find(stats.surfaceControl);
+            ASSERT_NE(expectedSurfaceResult, mExpectedSurfaceResults.end())
+                    << "unexpected surface control";
+            expectedSurfaceResult->second.verifySurfaceControlStats(stats, latchTime);
+        }
+    }
+
+private:
+    class ExpectedSurfaceResult {
+    public:
+        ExpectedSurfaceResult(ExpectedResult::Buffer bufferResult,
+                              ExpectedResult::PreviousBuffer previousBufferResult)
+              : mBufferResult(bufferResult), mPreviousBufferResult(previousBufferResult) {}
+
+        void verifySurfaceControlStats(const SurfaceControlStats& surfaceControlStats,
+                                       nsecs_t latchTime) const {
+            const auto& [surfaceControl, acquireTime, previousReleaseFence] = surfaceControlStats;
+
+            ASSERT_EQ(acquireTime > 0, mBufferResult == ExpectedResult::Buffer::ACQUIRED)
+                    << "bad acquire time";
+            ASSERT_LE(acquireTime, latchTime) << "acquire time should be <= latch time";
+
+            if (mPreviousBufferResult == ExpectedResult::PreviousBuffer::RELEASED) {
+                ASSERT_NE(previousReleaseFence, nullptr)
+                        << "failed to set release prev buffer fence";
+            } else if (mPreviousBufferResult == ExpectedResult::PreviousBuffer::NOT_RELEASED) {
+                ASSERT_EQ(previousReleaseFence, nullptr)
+                        << "should not have set released prev buffer fence";
+            }
+        }
+
+    private:
+        ExpectedResult::Buffer mBufferResult;
+        ExpectedResult::PreviousBuffer mPreviousBufferResult;
+    };
+
+    struct SCHash {
+        std::size_t operator()(const sp<SurfaceControl>& sc) const {
+            return std::hash<IBinder*>{}(sc->getHandle().get());
+        }
+    };
+    ExpectedResult::Transaction mTransactionResult = ExpectedResult::Transaction::NOT_PRESENTED;
+    nsecs_t mExpectedPresentTime = -1;
+    std::unordered_map<sp<SurfaceControl>, ExpectedSurfaceResult, SCHash> mExpectedSurfaceResults;
+};
+
+class CallbackHelper {
+public:
+    static void function(void* callbackContext, nsecs_t latchTime, const sp<Fence>& presentFence,
+                         const std::vector<SurfaceControlStats>& stats) {
+        if (!callbackContext) {
+            ALOGE("failed to get callback context");
+        }
+        CallbackHelper* helper = static_cast<CallbackHelper*>(callbackContext);
+        std::lock_guard lock(helper->mMutex);
+        helper->mCallbackDataQueue.emplace(latchTime, presentFence, stats);
+        helper->mConditionVariable.notify_all();
+    }
+
+    void getCallbackData(CallbackData* outData) {
+        std::unique_lock lock(mMutex);
+
+        if (mCallbackDataQueue.empty()) {
+            ASSERT_NE(mConditionVariable.wait_for(lock, std::chrono::seconds(3)),
+                      std::cv_status::timeout)
+                    << "did not receive callback";
+        }
+
+        *outData = std::move(mCallbackDataQueue.front());
+        mCallbackDataQueue.pop();
+    }
+
+    void verifyFinalState() {
+        // Wait to see if there are extra callbacks
+        std::this_thread::sleep_for(500ms);
+
+        std::lock_guard lock(mMutex);
+        EXPECT_EQ(mCallbackDataQueue.size(), 0) << "extra callbacks received";
+        mCallbackDataQueue = {};
+    }
+
+    void* getContext() { return static_cast<void*>(this); }
+
+    std::mutex mMutex;
+    std::condition_variable mConditionVariable;
+    std::queue<CallbackData> mCallbackDataQueue;
+};
+}
+} // namespace android
diff --git a/services/surfaceflinger/tests/utils/ColorUtils.h b/services/surfaceflinger/tests/utils/ColorUtils.h
new file mode 100644
index 0000000..07916b6
--- /dev/null
+++ b/services/surfaceflinger/tests/utils/ColorUtils.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 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.
+ */
+#pragma once
+
+#include <ui/ColorSpace.h>
+
+namespace android {
+
+namespace {
+
+struct Color {
+    uint8_t r;
+    uint8_t g;
+    uint8_t b;
+    uint8_t a;
+
+    static const Color RED;
+    static const Color GREEN;
+    static const Color BLUE;
+    static const Color WHITE;
+    static const Color BLACK;
+    static const Color TRANSPARENT;
+};
+
+const Color Color::RED{255, 0, 0, 255};
+const Color Color::GREEN{0, 255, 0, 255};
+const Color Color::BLUE{0, 0, 255, 255};
+const Color Color::WHITE{255, 255, 255, 255};
+const Color Color::BLACK{0, 0, 0, 255};
+const Color Color::TRANSPARENT{0, 0, 0, 0};
+
+class ColorTransformHelper {
+public:
+    static void DegammaColorSingle(half& s) {
+        if (s <= 0.03928f)
+            s = s / 12.92f;
+        else
+            s = pow((s + 0.055f) / 1.055f, 2.4f);
+    }
+
+    static void DegammaColor(half3& color) {
+        DegammaColorSingle(color.r);
+        DegammaColorSingle(color.g);
+        DegammaColorSingle(color.b);
+    }
+
+    static void GammaColorSingle(half& s) {
+        if (s <= 0.0031308f) {
+            s = s * 12.92f;
+        } else {
+            s = 1.055f * pow(s, (1.0f / 2.4f)) - 0.055f;
+        }
+    }
+
+    static void GammaColor(half3& color) {
+        GammaColorSingle(color.r);
+        GammaColorSingle(color.g);
+        GammaColorSingle(color.b);
+    }
+
+    static void applyMatrix(half3& color, const mat3& mat) {
+        half3 ret = half3(0);
+
+        for (int i = 0; i < 3; i++) {
+            for (int j = 0; j < 3; j++) {
+                ret[i] = ret[i] + color[j] * mat[j][i];
+            }
+        }
+        color = ret;
+    }
+};
+} // namespace
+} // namespace android
diff --git a/services/surfaceflinger/tests/utils/ScreenshotUtils.h b/services/surfaceflinger/tests/utils/ScreenshotUtils.h
new file mode 100644
index 0000000..02e7623
--- /dev/null
+++ b/services/surfaceflinger/tests/utils/ScreenshotUtils.h
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 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.
+ */
+#pragma once
+
+#include <ui/Rect.h>
+#include <utils/String8.h>
+#include "TransactionUtils.h"
+
+namespace android {
+
+namespace {
+
+// A ScreenCapture is a screenshot from SurfaceFlinger that can be used to check
+// individual pixel values for testing purposes.
+class ScreenCapture : public RefBase {
+public:
+    static void captureScreen(std::unique_ptr<ScreenCapture>* sc) {
+        captureScreen(sc, SurfaceComposerClient::getInternalDisplayToken());
+    }
+
+    static void captureScreen(std::unique_ptr<ScreenCapture>* sc, sp<IBinder> displayToken) {
+        const auto sf = ComposerService::getComposerService();
+        SurfaceComposerClient::Transaction().apply(true);
+
+        sp<GraphicBuffer> outBuffer;
+        ASSERT_EQ(NO_ERROR, sf->captureScreen(displayToken, &outBuffer, Rect(), 0, 0, false));
+        *sc = std::make_unique<ScreenCapture>(outBuffer);
+    }
+
+    static void captureLayers(std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
+                              Rect crop = Rect::EMPTY_RECT, float frameScale = 1.0) {
+        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+        SurfaceComposerClient::Transaction().apply(true);
+
+        sp<GraphicBuffer> outBuffer;
+        ASSERT_EQ(NO_ERROR, sf->captureLayers(parentHandle, &outBuffer, crop, frameScale));
+        *sc = std::make_unique<ScreenCapture>(outBuffer);
+    }
+
+    static void captureChildLayers(std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
+                                   Rect crop = Rect::EMPTY_RECT, float frameScale = 1.0) {
+        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+        SurfaceComposerClient::Transaction().apply(true);
+
+        sp<GraphicBuffer> outBuffer;
+        ASSERT_EQ(NO_ERROR, sf->captureLayers(parentHandle, &outBuffer, crop, frameScale, true));
+        *sc = std::make_unique<ScreenCapture>(outBuffer);
+    }
+
+    static void captureChildLayersExcluding(
+            std::unique_ptr<ScreenCapture>* sc, sp<IBinder>& parentHandle,
+            std::unordered_set<sp<IBinder>, ISurfaceComposer::SpHash<IBinder>> excludeLayers) {
+        sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+        SurfaceComposerClient::Transaction().apply(true);
+
+        sp<GraphicBuffer> outBuffer;
+        ASSERT_EQ(NO_ERROR,
+                  sf->captureLayers(parentHandle, &outBuffer, ui::Dataspace::V0_SRGB,
+                                    ui::PixelFormat::RGBA_8888, Rect::EMPTY_RECT, excludeLayers,
+                                    1.0f, true));
+        *sc = std::make_unique<ScreenCapture>(outBuffer);
+    }
+
+    void expectColor(const Rect& rect, const Color& color, uint8_t tolerance = 0) {
+        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
+        expectBufferColor(mOutBuffer, mPixels, rect, color, tolerance);
+    }
+
+    void expectBorder(const Rect& rect, const Color& color, uint8_t tolerance = 0) {
+        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
+        const bool leftBorder = rect.left > 0;
+        const bool topBorder = rect.top > 0;
+        const bool rightBorder = rect.right < int32_t(mOutBuffer->getWidth());
+        const bool bottomBorder = rect.bottom < int32_t(mOutBuffer->getHeight());
+
+        if (topBorder) {
+            Rect top(rect.left, rect.top - 1, rect.right, rect.top);
+            if (leftBorder) {
+                top.left -= 1;
+            }
+            if (rightBorder) {
+                top.right += 1;
+            }
+            expectColor(top, color, tolerance);
+        }
+        if (leftBorder) {
+            Rect left(rect.left - 1, rect.top, rect.left, rect.bottom);
+            expectColor(left, color, tolerance);
+        }
+        if (rightBorder) {
+            Rect right(rect.right, rect.top, rect.right + 1, rect.bottom);
+            expectColor(right, color, tolerance);
+        }
+        if (bottomBorder) {
+            Rect bottom(rect.left, rect.bottom, rect.right, rect.bottom + 1);
+            if (leftBorder) {
+                bottom.left -= 1;
+            }
+            if (rightBorder) {
+                bottom.right += 1;
+            }
+            expectColor(bottom, color, tolerance);
+        }
+    }
+
+    void expectQuadrant(const Rect& rect, const Color& topLeft, const Color& topRight,
+                        const Color& bottomLeft, const Color& bottomRight, bool filtered = false,
+                        uint8_t tolerance = 0) {
+        ASSERT_TRUE((rect.right - rect.left) % 2 == 0 && (rect.bottom - rect.top) % 2 == 0);
+
+        const int32_t centerX = rect.left + (rect.right - rect.left) / 2;
+        const int32_t centerY = rect.top + (rect.bottom - rect.top) / 2;
+        // avoid checking borders due to unspecified filtering behavior
+        const int32_t offsetX = filtered ? 2 : 0;
+        const int32_t offsetY = filtered ? 2 : 0;
+        expectColor(Rect(rect.left, rect.top, centerX - offsetX, centerY - offsetY), topLeft,
+                    tolerance);
+        expectColor(Rect(centerX + offsetX, rect.top, rect.right, centerY - offsetY), topRight,
+                    tolerance);
+        expectColor(Rect(rect.left, centerY + offsetY, centerX - offsetX, rect.bottom), bottomLeft,
+                    tolerance);
+        expectColor(Rect(centerX + offsetX, centerY + offsetY, rect.right, rect.bottom),
+                    bottomRight, tolerance);
+    }
+
+    void checkPixel(uint32_t x, uint32_t y, uint8_t r, uint8_t g, uint8_t b) {
+        ASSERT_EQ(HAL_PIXEL_FORMAT_RGBA_8888, mOutBuffer->getPixelFormat());
+        const uint8_t* pixel = mPixels + (4 * (y * mOutBuffer->getStride() + x));
+        if (r != pixel[0] || g != pixel[1] || b != pixel[2]) {
+            String8 err(String8::format("pixel @ (%3d, %3d): "
+                                        "expected [%3d, %3d, %3d], got [%3d, %3d, %3d]",
+                                        x, y, r, g, b, pixel[0], pixel[1], pixel[2]));
+            EXPECT_EQ(String8(), err) << err.string();
+        }
+    }
+
+    void expectFGColor(uint32_t x, uint32_t y) { checkPixel(x, y, 195, 63, 63); }
+
+    void expectBGColor(uint32_t x, uint32_t y) { checkPixel(x, y, 63, 63, 195); }
+
+    void expectChildColor(uint32_t x, uint32_t y) { checkPixel(x, y, 200, 200, 200); }
+
+    explicit ScreenCapture(const sp<GraphicBuffer>& outBuffer) : mOutBuffer(outBuffer) {
+        mOutBuffer->lock(GRALLOC_USAGE_SW_READ_OFTEN, reinterpret_cast<void**>(&mPixels));
+    }
+
+    ~ScreenCapture() { mOutBuffer->unlock(); }
+
+private:
+    sp<GraphicBuffer> mOutBuffer;
+    uint8_t* mPixels = nullptr;
+};
+} // namespace
+} // namespace android
diff --git a/services/surfaceflinger/tests/utils/TransactionUtils.h b/services/surfaceflinger/tests/utils/TransactionUtils.h
new file mode 100644
index 0000000..f6b33a9
--- /dev/null
+++ b/services/surfaceflinger/tests/utils/TransactionUtils.h
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#pragma once
+
+//#include <algorithm>
+#include <chrono>
+//#include <cinttypes>
+//#include <functional>
+//#include <limits>
+//#include <ostream>
+//#include <thread>
+#include <gtest/gtest.h>
+
+#include <android/native_window.h>
+#include <hardware/hwcomposer_defs.h>
+
+#include <binder/IPCThreadState.h>
+
+#include <gui/Surface.h>
+#include <gui/SurfaceComposerClient.h>
+
+#include <private/gui/ComposerService.h>
+
+#include <ui/GraphicBuffer.h>
+#include <ui/Rect.h>
+
+#include "ColorUtils.h"
+//#include <sys/types.h>
+//#include <unistd.h>
+
+namespace android {
+
+namespace {
+
+using namespace std::chrono_literals;
+
+std::ostream& operator<<(std::ostream& os, const Color& color) {
+    os << int(color.r) << ", " << int(color.g) << ", " << int(color.b) << ", " << int(color.a);
+    return os;
+}
+
+// Fill a region with the specified color.
+void fillANativeWindowBufferColor(const ANativeWindow_Buffer& buffer, const Rect& rect,
+                                  const Color& color) {
+    Rect r(0, 0, buffer.width, buffer.height);
+    if (!r.intersect(rect, &r)) {
+        return;
+    }
+
+    int32_t width = r.right - r.left;
+    int32_t height = r.bottom - r.top;
+
+    for (int32_t row = 0; row < height; row++) {
+        uint8_t* dst =
+                static_cast<uint8_t*>(buffer.bits) + (buffer.stride * (r.top + row) + r.left) * 4;
+        for (int32_t column = 0; column < width; column++) {
+            dst[0] = color.r;
+            dst[1] = color.g;
+            dst[2] = color.b;
+            dst[3] = color.a;
+            dst += 4;
+        }
+    }
+}
+
+// Fill a region with the specified color.
+void fillGraphicBufferColor(const sp<GraphicBuffer>& buffer, const Rect& rect, const Color& color) {
+    Rect r(0, 0, buffer->width, buffer->height);
+    if (!r.intersect(rect, &r)) {
+        return;
+    }
+
+    int32_t width = r.right - r.left;
+    int32_t height = r.bottom - r.top;
+
+    uint8_t* pixels;
+    buffer->lock(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
+                 reinterpret_cast<void**>(&pixels));
+
+    for (int32_t row = 0; row < height; row++) {
+        uint8_t* dst = pixels + (buffer->getStride() * (r.top + row) + r.left) * 4;
+        for (int32_t column = 0; column < width; column++) {
+            dst[0] = color.r;
+            dst[1] = color.g;
+            dst[2] = color.b;
+            dst[3] = color.a;
+            dst += 4;
+        }
+    }
+    buffer->unlock();
+}
+
+// Check if a region has the specified color.
+void expectBufferColor(const sp<GraphicBuffer>& outBuffer, uint8_t* pixels, const Rect& rect,
+                       const Color& color, uint8_t tolerance) {
+    int32_t x = rect.left;
+    int32_t y = rect.top;
+    int32_t width = rect.right - rect.left;
+    int32_t height = rect.bottom - rect.top;
+
+    int32_t bufferWidth = int32_t(outBuffer->getWidth());
+    int32_t bufferHeight = int32_t(outBuffer->getHeight());
+    if (x + width > bufferWidth) {
+        x = std::min(x, bufferWidth);
+        width = bufferWidth - x;
+    }
+    if (y + height > bufferHeight) {
+        y = std::min(y, bufferHeight);
+        height = bufferHeight - y;
+    }
+
+    auto colorCompare = [tolerance](uint8_t a, uint8_t b) {
+        uint8_t tmp = a >= b ? a - b : b - a;
+        return tmp <= tolerance;
+    };
+    for (int32_t j = 0; j < height; j++) {
+        const uint8_t* src = pixels + (outBuffer->getStride() * (y + j) + x) * 4;
+        for (int32_t i = 0; i < width; i++) {
+            const uint8_t expected[4] = {color.r, color.g, color.b, color.a};
+            EXPECT_TRUE(std::equal(src, src + 4, expected, colorCompare))
+                    << "pixel @ (" << x + i << ", " << y + j << "): "
+                    << "expected (" << color << "), "
+                    << "got (" << Color{src[0], src[1], src[2], src[3]} << ")";
+            src += 4;
+        }
+    }
+}
+
+using Transaction = SurfaceComposerClient::Transaction;
+
+// Fill an RGBA_8888 formatted surface with a single color.
+static void fillSurfaceRGBA8(const sp<SurfaceControl>& sc, uint8_t r, uint8_t g, uint8_t b,
+                             bool unlock = true) {
+    ANativeWindow_Buffer outBuffer;
+    sp<Surface> s = sc->getSurface();
+    ASSERT_TRUE(s != nullptr);
+    ASSERT_EQ(NO_ERROR, s->lock(&outBuffer, nullptr));
+    uint8_t* img = reinterpret_cast<uint8_t*>(outBuffer.bits);
+    for (int y = 0; y < outBuffer.height; y++) {
+        for (int x = 0; x < outBuffer.width; x++) {
+            uint8_t* pixel = img + (4 * (y * outBuffer.stride + x));
+            pixel[0] = r;
+            pixel[1] = g;
+            pixel[2] = b;
+            pixel[3] = 255;
+        }
+    }
+    if (unlock) {
+        ASSERT_EQ(NO_ERROR, s->unlockAndPost());
+    }
+}
+
+enum class RenderPath { SCREENSHOT, VIRTUAL_DISPLAY };
+
+// Environment for starting up binder threads. This is required for testing
+// virtual displays, as BufferQueue parameters may be queried over binder.
+class BinderEnvironment : public ::testing::Environment {
+public:
+    void SetUp() override { ProcessState::self()->startThreadPool(); }
+};
+
+/** RAII Wrapper around get/seteuid */
+class UIDFaker {
+    uid_t oldId;
+
+public:
+    UIDFaker(uid_t uid) {
+        oldId = geteuid();
+        seteuid(uid);
+    }
+    ~UIDFaker() { seteuid(oldId); }
+};
+} // namespace
+} // namespace android