diff --git a/services/surfaceflinger/tests/Transaction_test.cpp b/services/surfaceflinger/tests/Transaction_test.cpp
index acb263a..ece61df 100644
--- a/services/surfaceflinger/tests/Transaction_test.cpp
+++ b/services/surfaceflinger/tests/Transaction_test.cpp
@@ -136,7 +136,9 @@
                                            int32_t bufferWidth, int32_t bufferHeight) {
         ANativeWindow_Buffer buffer;
         ASSERT_NO_FATAL_FAILURE(buffer = getBufferQueueLayerBuffer(layer));
-        fillANativeWindowBufferColor(buffer, Rect(0, 0, bufferWidth, bufferHeight), color);
+        TransactionUtils::fillANativeWindowBufferColor(buffer,
+                                                       Rect(0, 0, bufferWidth, bufferHeight),
+                                                       color);
         postBufferQueueLayerBuffer(layer);
     }
 
@@ -147,7 +149,8 @@
                                   BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                           BufferUsage::COMPOSER_OVERLAY,
                                   "test");
-        fillGraphicBufferColor(buffer, Rect(0, 0, bufferWidth, bufferHeight), color);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, bufferWidth, bufferHeight),
+                                                 color);
         Transaction().setBuffer(layer, buffer).apply();
     }
 
@@ -193,11 +196,15 @@
 
         const int32_t halfW = bufferWidth / 2;
         const int32_t halfH = bufferHeight / 2;
-        fillANativeWindowBufferColor(buffer, Rect(0, 0, halfW, halfH), topLeft);
-        fillANativeWindowBufferColor(buffer, Rect(halfW, 0, bufferWidth, halfH), topRight);
-        fillANativeWindowBufferColor(buffer, Rect(0, halfH, halfW, bufferHeight), bottomLeft);
-        fillANativeWindowBufferColor(buffer, Rect(halfW, halfH, bufferWidth, bufferHeight),
-                                     bottomRight);
+        TransactionUtils::fillANativeWindowBufferColor(buffer, Rect(0, 0, halfW, halfH), topLeft);
+        TransactionUtils::fillANativeWindowBufferColor(buffer, Rect(halfW, 0, bufferWidth, halfH),
+                                                       topRight);
+        TransactionUtils::fillANativeWindowBufferColor(buffer, Rect(0, halfH, halfW, bufferHeight),
+                                                       bottomLeft);
+        TransactionUtils::fillANativeWindowBufferColor(buffer,
+                                                       Rect(halfW, halfH, bufferWidth,
+                                                            bufferHeight),
+                                                       bottomRight);
 
         postBufferQueueLayerBuffer(layer);
     }
@@ -216,10 +223,14 @@
 
         const int32_t halfW = bufferWidth / 2;
         const int32_t halfH = bufferHeight / 2;
-        fillGraphicBufferColor(buffer, Rect(0, 0, halfW, halfH), topLeft);
-        fillGraphicBufferColor(buffer, Rect(halfW, 0, bufferWidth, halfH), topRight);
-        fillGraphicBufferColor(buffer, Rect(0, halfH, halfW, bufferHeight), bottomLeft);
-        fillGraphicBufferColor(buffer, Rect(halfW, halfH, bufferWidth, bufferHeight), bottomRight);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, halfW, halfH), topLeft);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(halfW, 0, bufferWidth, halfH),
+                                                 topRight);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, halfH, halfW, bufferHeight),
+                                                 bottomLeft);
+        TransactionUtils::fillGraphicBufferColor(buffer,
+                                                 Rect(halfW, halfH, bufferWidth, bufferHeight),
+                                                 bottomRight);
 
         Transaction().setBuffer(layer, buffer).setSize(layer, bufferWidth, bufferHeight).apply();
     }
@@ -1093,8 +1104,10 @@
 
     ANativeWindow_Buffer buffer;
     ASSERT_NO_FATAL_FAILURE(buffer = getBufferQueueLayerBuffer(layer));
-    ASSERT_NO_FATAL_FAILURE(fillANativeWindowBufferColor(buffer, top, Color::TRANSPARENT));
-    ASSERT_NO_FATAL_FAILURE(fillANativeWindowBufferColor(buffer, bottom, Color::RED));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillANativeWindowBufferColor(buffer, top, Color::TRANSPARENT));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillANativeWindowBufferColor(buffer, bottom, Color::RED));
     // setTransparentRegionHint always applies to the following buffer
     Transaction().setTransparentRegionHint(layer, Region(top)).apply();
     ASSERT_NO_FATAL_FAILURE(postBufferQueueLayerBuffer(layer));
@@ -1114,8 +1127,10 @@
     }
 
     ASSERT_NO_FATAL_FAILURE(buffer = getBufferQueueLayerBuffer(layer));
-    ASSERT_NO_FATAL_FAILURE(fillANativeWindowBufferColor(buffer, top, Color::RED));
-    ASSERT_NO_FATAL_FAILURE(fillANativeWindowBufferColor(buffer, bottom, Color::TRANSPARENT));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillANativeWindowBufferColor(buffer, top, Color::RED));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillANativeWindowBufferColor(buffer, bottom, Color::TRANSPARENT));
     ASSERT_NO_FATAL_FAILURE(postBufferQueueLayerBuffer(layer));
     {
         SCOPED_TRACE("bottom transparent");
@@ -1138,8 +1153,9 @@
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
 
-    ASSERT_NO_FATAL_FAILURE(fillGraphicBufferColor(buffer, top, Color::TRANSPARENT));
-    ASSERT_NO_FATAL_FAILURE(fillGraphicBufferColor(buffer, bottom, Color::RED));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillGraphicBufferColor(buffer, top, Color::TRANSPARENT));
+    ASSERT_NO_FATAL_FAILURE(TransactionUtils::fillGraphicBufferColor(buffer, bottom, Color::RED));
     Transaction()
             .setTransparentRegionHint(layer, Region(top))
             .setBuffer(layer, buffer)
@@ -1165,8 +1181,9 @@
                                        BufferUsage::COMPOSER_OVERLAY,
                                "test");
 
-    ASSERT_NO_FATAL_FAILURE(fillGraphicBufferColor(buffer, top, Color::RED));
-    ASSERT_NO_FATAL_FAILURE(fillGraphicBufferColor(buffer, bottom, Color::TRANSPARENT));
+    ASSERT_NO_FATAL_FAILURE(TransactionUtils::fillGraphicBufferColor(buffer, top, Color::RED));
+    ASSERT_NO_FATAL_FAILURE(
+            TransactionUtils::fillGraphicBufferColor(buffer, bottom, Color::TRANSPARENT));
     Transaction().setBuffer(layer, buffer).apply();
     {
         SCOPED_TRACE("bottom transparent");
@@ -1907,8 +1924,8 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 16), Color::BLUE);
-    fillGraphicBufferColor(buffer, Rect(0, 16, 32, 64), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 16), Color::BLUE);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 16, 32, 64), Color::RED);
 
     Transaction().setFrame(layer, Rect(0, 0, 64, 64)).apply();
 
@@ -2302,7 +2319,7 @@
                                            BufferUsage::COMPOSER_OVERLAY,
                                    "test");
         Color color = colors[idx % colors.size()];
-        fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
         idx++;
     }
 
@@ -2338,7 +2355,7 @@
                                            BufferUsage::COMPOSER_OVERLAY,
                                    "test");
         Color color = colors[idx % colors.size()];
-        fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
         idx++;
     }
 
@@ -2374,7 +2391,7 @@
                                            BufferUsage::COMPOSER_OVERLAY,
                                    "test");
         Color color = colors[idx % colors.size()];
-        fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
+        TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), color);
         idx++;
     }
 
@@ -2471,7 +2488,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     sp<Fence> fence;
     if (getBuffer(nullptr, &fence) != NO_ERROR) {
@@ -2500,7 +2517,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     sp<Fence> fence = Fence::NO_FENCE;
 
@@ -2524,7 +2541,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     Transaction()
             .setBuffer(layer, buffer)
@@ -2546,7 +2563,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     HdrMetadata hdrMetadata;
     hdrMetadata.validTypes = 0;
@@ -2570,7 +2587,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     Region region;
     region.set(32, 32);
@@ -2594,7 +2611,7 @@
                               BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
                                       BufferUsage::COMPOSER_OVERLAY,
                               "test");
-    fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
+    TransactionUtils::fillGraphicBufferColor(buffer, Rect(0, 0, 32, 32), Color::RED);
 
     Transaction()
             .setBuffer(layer, buffer)
@@ -3661,7 +3678,7 @@
                                                displayHeight, 0);
         ASSERT_TRUE(mBGSurfaceControl != nullptr);
         ASSERT_TRUE(mBGSurfaceControl->isValid());
-        fillSurfaceRGBA8(mBGSurfaceControl, 63, 63, 195);
+        TransactionUtils::fillSurfaceRGBA8(mBGSurfaceControl, 63, 63, 195);
 
         // Foreground surface
         mFGSurfaceControl = createLayer(String8("FG Test Surface"), 64, 64, 0);
@@ -3669,14 +3686,14 @@
         ASSERT_TRUE(mFGSurfaceControl != nullptr);
         ASSERT_TRUE(mFGSurfaceControl->isValid());
 
-        fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
+        TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
 
         // Synchronization surface
         mSyncSurfaceControl = createLayer(String8("Sync Test Surface"), 1, 1, 0);
         ASSERT_TRUE(mSyncSurfaceControl != nullptr);
         ASSERT_TRUE(mSyncSurfaceControl->isValid());
 
-        fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+        TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
 
         asTransaction([&](Transaction& t) {
             t.setDisplayLayerStack(display, 0);
@@ -3705,9 +3722,9 @@
         // posting three buffers to it should ensure that at least two
         // SurfaceFlinger::handlePageFlip calls have been made, which should
         // guaranteed that a buffer posted to another Surface has been retired.
-        fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
-        fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
-        fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+        TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+        TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+        TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
     }
 
 
@@ -3724,7 +3741,7 @@
     std::unique_ptr<ScreenCapture> sc;
 
     sp<SurfaceControl> relative = createLayer(String8("relativeTestSurface"), 10, 10, 0);
-    fillSurfaceRGBA8(relative, 10, 10, 10);
+    TransactionUtils::fillSurfaceRGBA8(relative, 10, 10, 10);
     waitForPostedBuffers();
 
     Transaction{}
@@ -3765,7 +3782,9 @@
         sc->expectBGColor(128, 128);
     }
 
-    void lockAndFillFGBuffer() { fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63, false); }
+    void lockAndFillFGBuffer() {
+        TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63, false);
+    }
 
     void unlockFGBuffer() {
         sp<Surface> s = mFGSurfaceControl->getSurface();
@@ -3774,7 +3793,7 @@
     }
 
     void completeFGResize() {
-        fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
+        TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
         waitForPostedBuffers();
     }
     void restoreInitialState() {
@@ -3842,7 +3861,7 @@
     }
 
     // should trigger the first deferred transaction, but not the second one
-    fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+    TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
     {
         SCOPED_TRACE("after first trigger");
         ScreenCapture::captureScreen(&sc);
@@ -3855,7 +3874,7 @@
     asTransaction([&](Transaction& t) { t.setAlpha(mFGSurfaceControl, 1.0); });
 
     // trigger the second deferred transaction
-    fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
+    TransactionUtils::fillSurfaceRGBA8(mSyncSurfaceControl, 31, 31, 31);
     {
         SCOPED_TRACE("after second trigger");
         ScreenCapture::captureScreen(&sc);
@@ -3873,7 +3892,7 @@
                           PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
     sp<SurfaceControl> childBuffer = createSurface(mClient, "Buffered child", 20, 20,
                                                    PIXEL_FORMAT_RGBA_8888, 0, childNoBuffer.get());
-    fillSurfaceRGBA8(childBuffer, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(childBuffer, 200, 200, 200);
     SurfaceComposerClient::Transaction{}
             .setCrop_legacy(childNoBuffer, Rect(0, 0, 10, 10))
             .show(childNoBuffer)
@@ -3948,7 +3967,7 @@
         LayerUpdateTest::SetUp();
         mChild = createSurface(mClient, "Child surface", 10, 15, PIXEL_FORMAT_RGBA_8888, 0,
                                mFGSurfaceControl.get());
-        fillSurfaceRGBA8(mChild, 200, 200, 200);
+        TransactionUtils::fillSurfaceRGBA8(mChild, 200, 200, 200);
 
         {
             SCOPED_TRACE("before anything");
@@ -4079,9 +4098,9 @@
 }
 
 TEST_F(ChildLayerTest, ChildLayerAlpha) {
-    fillSurfaceRGBA8(mBGSurfaceControl, 0, 0, 254);
-    fillSurfaceRGBA8(mFGSurfaceControl, 254, 0, 0);
-    fillSurfaceRGBA8(mChild, 0, 254, 0);
+    TransactionUtils::fillSurfaceRGBA8(mBGSurfaceControl, 0, 0, 254);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 254, 0, 0);
+    TransactionUtils::fillSurfaceRGBA8(mChild, 0, 254, 0);
     waitForPostedBuffers();
 
     asTransaction([&](Transaction& t) {
@@ -4149,7 +4168,7 @@
 TEST_F(ChildLayerTest, ChildrenSurviveParentDestruction) {
     sp<SurfaceControl> mGrandChild =
             createSurface(mClient, "Grand Child", 10, 10, PIXEL_FORMAT_RGBA_8888, 0, mChild.get());
-    fillSurfaceRGBA8(mGrandChild, 111, 111, 111);
+    TransactionUtils::fillSurfaceRGBA8(mGrandChild, 111, 111, 111);
 
     {
         SCOPED_TRACE("Grandchild visible");
@@ -4179,7 +4198,7 @@
 TEST_F(ChildLayerTest, ChildrenRelativeZSurvivesParentDestruction) {
     sp<SurfaceControl> mGrandChild =
             createSurface(mClient, "Grand Child", 10, 10, PIXEL_FORMAT_RGBA_8888, 0, mChild.get());
-    fillSurfaceRGBA8(mGrandChild, 111, 111, 111);
+    TransactionUtils::fillSurfaceRGBA8(mGrandChild, 111, 111, 111);
 
     // draw grand child behind the foreground surface
     asTransaction([&](Transaction& t) {
@@ -4244,7 +4263,7 @@
 
     ASSERT_TRUE(mChildNewClient->isValid());
 
-    fillSurfaceRGBA8(mChildNewClient, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(mChildNewClient, 200, 200, 200);
 
     asTransaction([&](Transaction& t) {
         t.hide(mChild);
@@ -4285,7 +4304,7 @@
     ASSERT_TRUE(childNewClient != nullptr);
     ASSERT_TRUE(childNewClient->isValid());
 
-    fillSurfaceRGBA8(childNewClient, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(childNewClient, 200, 200, 200);
 
     Transaction()
             .hide(mChild)
@@ -4339,7 +4358,7 @@
     ASSERT_TRUE(childNewClient != nullptr);
     ASSERT_TRUE(childNewClient->isValid());
 
-    fillSurfaceRGBA8(childNewClient, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(childNewClient, 200, 200, 200);
 
     Transaction()
             .hide(mChild)
@@ -4428,7 +4447,7 @@
     auto anw = static_cast<ANativeWindow*>(s.get());
     native_window_set_buffers_transform(anw, NATIVE_WINDOW_TRANSFORM_ROT_90);
     native_window_set_buffers_dimensions(anw, 64, 128);
-    fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
     waitForPostedBuffers();
 
     {
@@ -4448,7 +4467,7 @@
         t.setPosition(mFGSurfaceControl, 0, 0);
         t.setSize(mChild, 100, 100);
     });
-    fillSurfaceRGBA8(mChild, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(mChild, 200, 200, 200);
 
     {
         mCapture = screenshot();
@@ -4464,7 +4483,7 @@
     // Apply a 90 transform on the buffer.
     native_window_set_buffers_transform(anw, NATIVE_WINDOW_TRANSFORM_ROT_90);
     native_window_set_buffers_dimensions(anw, 64, 128);
-    fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
     waitForPostedBuffers();
 
     // The child should be cropped by the new parent bounds.
@@ -4485,7 +4504,7 @@
         t.setPosition(mFGSurfaceControl, 0, 0);
         t.setSize(mChild, 200, 200);
     });
-    fillSurfaceRGBA8(mChild, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(mChild, 200, 200, 200);
 
     {
         mCapture = screenshot();
@@ -4537,7 +4556,7 @@
     // have an effective scale of 2.0 applied to the buffer along with a rotation transform.
     native_window_set_buffers_transform(anw, NATIVE_WINDOW_TRANSFORM_ROT_90);
     native_window_set_buffers_dimensions(anw, 32, 64);
-    fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 195, 63, 63);
     waitForPostedBuffers();
 
     // The child should ignore the buffer transform but apply the 2.0 scale from parent.
@@ -4570,13 +4589,13 @@
     // frame because SurfaceFlinger would never process the deferred transaction and would therefore
     // never acquire/release the first buffer
     ALOGI("Filling 1");
-    fillSurfaceRGBA8(mFGSurfaceControl, 0, 255, 0);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 0, 255, 0);
     ALOGI("Filling 2");
-    fillSurfaceRGBA8(mFGSurfaceControl, 0, 0, 255);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 0, 0, 255);
     ALOGI("Filling 3");
-    fillSurfaceRGBA8(mFGSurfaceControl, 255, 0, 0);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 255, 0, 0);
     ALOGI("Filling 4");
-    fillSurfaceRGBA8(mFGSurfaceControl, 0, 255, 0);
+    TransactionUtils::fillSurfaceRGBA8(mFGSurfaceControl, 0, 255, 0);
 }
 
 TEST_F(ChildLayerTest, Reparent) {
@@ -4641,7 +4660,7 @@
     ASSERT_TRUE(newSurface != nullptr);
     ASSERT_TRUE(newSurface->isValid());
 
-    fillSurfaceRGBA8(newSurface, 63, 195, 63);
+    TransactionUtils::fillSurfaceRGBA8(newSurface, 63, 195, 63);
     asTransaction([&](Transaction& t) {
         t.hide(mChild);
         t.show(newSurface);
@@ -4673,7 +4692,7 @@
 TEST_F(ChildLayerTest, NestedChildren) {
     sp<SurfaceControl> grandchild = createSurface(mClient, "Grandchild surface", 10, 10,
                                                   PIXEL_FORMAT_RGBA_8888, 0, mChild.get());
-    fillSurfaceRGBA8(grandchild, 50, 50, 50);
+    TransactionUtils::fillSurfaceRGBA8(grandchild, 50, 50, 50);
 
     {
         mCapture = screenshot();
@@ -4685,7 +4704,7 @@
 
 TEST_F(ChildLayerTest, ChildLayerRelativeLayer) {
     sp<SurfaceControl> relative = createLayer(String8("Relative surface"), 128, 128, 0);
-    fillSurfaceRGBA8(relative, 255, 255, 255);
+    TransactionUtils::fillSurfaceRGBA8(relative, 255, 255, 255);
 
     Transaction t;
     t.setLayer(relative, INT32_MAX)
@@ -4922,7 +4941,7 @@
 
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
 
     SurfaceComposerClient::Transaction().show(child).apply(true);
 
@@ -4937,7 +4956,7 @@
 
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
 
     SurfaceComposerClient::Transaction().show(child).apply(true);
 
@@ -4952,10 +4971,10 @@
 
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
     sp<SurfaceControl> child2 = createSurface(mClient, "Child surface", 10, 10,
                                               PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child2, 200, 0, 200);
+    TransactionUtils::fillSurfaceRGBA8(child2, 200, 0, 200);
 
     SurfaceComposerClient::Transaction()
             .show(child)
@@ -4976,13 +4995,13 @@
 
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
     sp<SurfaceControl> child2 = createSurface(mClient, "Child surface", 10, 10,
                                               PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child2, 200, 0, 200);
+    TransactionUtils::fillSurfaceRGBA8(child2, 200, 0, 200);
     sp<SurfaceControl> child3 = createSurface(mClient, "Child surface", 10, 10,
                                               PIXEL_FORMAT_RGBA_8888, 0, child2.get());
-    fillSurfaceRGBA8(child2, 200, 0, 200);
+    TransactionUtils::fillSurfaceRGBA8(child2, 200, 0, 200);
 
     SurfaceComposerClient::Transaction()
             .show(child)
@@ -5002,7 +5021,7 @@
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
 
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
 
     SurfaceComposerClient::Transaction().show(child).apply(true);
 
@@ -5022,8 +5041,8 @@
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
     ASSERT_NE(nullptr, child.get()) << "failed to create surface";
     sp<SurfaceControl> relative = createLayer(String8("Relative surface"), 10, 10, 0);
-    fillSurfaceRGBA8(child, 200, 200, 200);
-    fillSurfaceRGBA8(relative, 100, 100, 100);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(relative, 100, 100, 100);
 
     SurfaceComposerClient::Transaction()
             .show(child)
@@ -5045,8 +5064,8 @@
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
     sp<SurfaceControl> relative = createSurface(mClient, "Relative surface", 10, 10,
                                                 PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
-    fillSurfaceRGBA8(relative, 100, 100, 100);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(relative, 100, 100, 100);
 
     SurfaceComposerClient::Transaction()
             .show(child)
@@ -5075,7 +5094,7 @@
 
         mChild = createSurface(mClient, "Child surface", 10, 10, PIXEL_FORMAT_RGBA_8888, 0,
                                mFGSurfaceControl.get());
-        fillSurfaceRGBA8(mChild, 200, 200, 200);
+        TransactionUtils::fillSurfaceRGBA8(mChild, 200, 200, 200);
 
         SurfaceComposerClient::Transaction().show(mChild).apply(true);
     }
@@ -5138,12 +5157,12 @@
 
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
 
     sp<SurfaceControl> grandchild = createSurface(mClient, "Grandchild surface", 5, 5,
                                                   PIXEL_FORMAT_RGBA_8888, 0, child.get());
 
-    fillSurfaceRGBA8(grandchild, 50, 50, 50);
+    TransactionUtils::fillSurfaceRGBA8(grandchild, 50, 50, 50);
     SurfaceComposerClient::Transaction()
             .show(child)
             .setPosition(grandchild, 5, 5)
@@ -5160,7 +5179,7 @@
 TEST_F(ScreenCaptureTest, CaptureChildOnly) {
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
     auto childHandle = child->getHandle();
 
     SurfaceComposerClient::Transaction().setPosition(child, 5, 5).show(child).apply(true);
@@ -5174,12 +5193,12 @@
 TEST_F(ScreenCaptureTest, CaptureGrandchildOnly) {
     sp<SurfaceControl> child = createSurface(mClient, "Child surface", 10, 10,
                                              PIXEL_FORMAT_RGBA_8888, 0, mFGSurfaceControl.get());
-    fillSurfaceRGBA8(child, 200, 200, 200);
+    TransactionUtils::fillSurfaceRGBA8(child, 200, 200, 200);
     auto childHandle = child->getHandle();
 
     sp<SurfaceControl> grandchild = createSurface(mClient, "Grandchild surface", 5, 5,
                                                   PIXEL_FORMAT_RGBA_8888, 0, child.get());
-    fillSurfaceRGBA8(grandchild, 50, 50, 50);
+    TransactionUtils::fillSurfaceRGBA8(grandchild, 50, 50, 50);
 
     SurfaceComposerClient::Transaction()
             .show(child)
@@ -5674,8 +5693,8 @@
         ASSERT_NO_FATAL_FAILURE(slotToBuffer(slot1, &buf1));
         sp<GraphicBuffer> buf2;
         ASSERT_NO_FATAL_FAILURE(slotToBuffer(slot2, &buf2));
-        fillGraphicBufferColor(buf1, Rect(width, height), color);
-        fillGraphicBufferColor(buf2, Rect(width, height), color);
+        TransactionUtils::fillGraphicBufferColor(buf1, Rect(width, height), color);
+        TransactionUtils::fillGraphicBufferColor(buf2, Rect(width, height), color);
 
         const auto displayTime = systemTime() + milliseconds_to_nanoseconds(100);
         ASSERT_NO_FATAL_FAILURE(queue(slot1, Region::INVALID_REGION, displayTime));
diff --git a/services/surfaceflinger/tests/utils/ScreenshotUtils.h b/services/surfaceflinger/tests/utils/ScreenshotUtils.h
index 02e7623..5480b00 100644
--- a/services/surfaceflinger/tests/utils/ScreenshotUtils.h
+++ b/services/surfaceflinger/tests/utils/ScreenshotUtils.h
@@ -76,7 +76,7 @@
 
     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);
+        TransactionUtils::expectBufferColor(mOutBuffer, mPixels, rect, color, tolerance);
     }
 
     void expectBorder(const Rect& rect, const Color& color, uint8_t tolerance = 0) {
diff --git a/services/surfaceflinger/tests/utils/TransactionUtils.h b/services/surfaceflinger/tests/utils/TransactionUtils.h
index f6b33a9..22df255 100644
--- a/services/surfaceflinger/tests/utils/TransactionUtils.h
+++ b/services/surfaceflinger/tests/utils/TransactionUtils.h
@@ -16,13 +16,7 @@
 
 #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>
@@ -39,130 +33,131 @@
 #include <ui/Rect.h>
 
 #include "ColorUtils.h"
-//#include <sys/types.h>
-//#include <unistd.h>
 
 namespace android {
 
 namespace {
 
 using namespace std::chrono_literals;
+using Transaction = SurfaceComposerClient::Transaction;
 
 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;
-    }
+class TransactionUtils {
+public:
+    // Fill a region with the specified color.
+    static 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;
+        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;
+        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;
+    // Fill a region with the specified color.
+    static 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();
     }
 
-    int32_t width = r.right - r.left;
-    int32_t height = r.bottom - r.top;
+    // Check if a region has the specified color.
+    static 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;
 
-    uint8_t* pixels;
-    buffer->lock(GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_OFTEN,
-                 reinterpret_cast<void**>(&pixels));
+        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;
+        }
 
-    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;
+        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;
+            }
         }
     }
-    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;
+    // 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());
         }
     }
-}
-
-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 };