Add display-resolution caching to GPU IDC

cc/tiles/gpu_image_decode_controller_unittest.cc

Index: cc/tiles/gpu_image_decode_controller_unittest.cc
diff --git a/cc/tiles/gpu_image_decode_controller_unittest.cc b/cc/tiles/gpu_image_decode_controller_unittest.cc
index a7c3f111d5d03d74ff91e1b60aad2726c9aab4e2..1a34568be204f0392e27cdc92e73c1534b64a7e1 100644
--- a/cc/tiles/gpu_image_decode_controller_unittest.cc
+++ b/cc/tiles/gpu_image_decode_controller_unittest.cc
@@ -50,7 +50,7 @@ TEST(GpuImageDecodeControllerTest, GetTaskForImageSameImage) {
 
   DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
                        quality,
-                       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+                       CreateMatrix(SkSize::Make(1.5f, 1.5f), is_decomposable));
   scoped_refptr<TileTask> task;
   bool need_unref = controller.GetTaskForImageAndRef(
       draw_image, ImageDecodeController::TracingInfo(), &task);
@@ -73,6 +73,71 @@ TEST(GpuImageDecodeControllerTest, GetTaskForImageSameImage) {
   controller.UnrefImage(draw_image);
 }
 
+TEST(GpuImageDecodeControllerTest, GetTaskForImageSmallerScale) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  sk_sp<SkImage> image = CreateImage(100, 100);
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
+                       quality,
+                       CreateMatrix(SkSize::Make(1.5f, 1.5f), is_decomposable));
+  scoped_refptr<TileTask> task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      draw_image, ImageDecodeController::TracingInfo(), &task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task);
+
+  DrawImage another_draw_image(
+      image, SkIRect::MakeWH(image->width(), image->height()), quality,
+      CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> another_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      another_draw_image, ImageDecodeController::TracingInfo(), &another_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task.get() == another_task.get());
+
+  TestTileTaskRunner::ProcessTask(task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(task.get());
+
+  controller.UnrefImage(draw_image);
+  controller.UnrefImage(another_draw_image);
+}
+
+TEST(GpuImageDecodeControllerTest, GetTaskForImageLowerQuality) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  sk_sp<SkImage> image = CreateImage(100, 100);
+  bool is_decomposable = true;
+  SkMatrix matrix = CreateMatrix(SkSize::Make(0.4f, 0.4f), is_decomposable);
+
+  DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
+                       kHigh_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      draw_image, ImageDecodeController::TracingInfo(), &task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task);
+
+  DrawImage another_draw_image(image,
+                               SkIRect::MakeWH(image->width(), image->height()),
+                               kLow_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> another_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      another_draw_image, ImageDecodeController::TracingInfo(), &another_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task.get() == another_task.get());
+
+  TestTileTaskRunner::ProcessTask(task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(task.get());
+
+  controller.UnrefImage(draw_image);
+  controller.UnrefImage(another_draw_image);
+}
+
 TEST(GpuImageDecodeControllerTest, GetTaskForImageDifferentImage) {
   auto context_provider = TestContextProvider::Create();
   context_provider->BindToCurrentThread();
@@ -111,6 +176,138 @@ TEST(GpuImageDecodeControllerTest, GetTaskForImageDifferentImage) {
   controller.UnrefImage(second_draw_image);
 }
 
+TEST(GpuImageDecodeControllerTest, GetTaskForImageLargerScale) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  sk_sp<SkImage> first_image = CreateImage(100, 100);
+  DrawImage first_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> first_task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      first_draw_image, ImageDecodeController::TracingInfo(), &first_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(first_task);
+
+  TestTileTaskRunner::ProcessTask(first_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(first_task.get());
+
+  controller.UnrefImage(first_draw_image);
+
+  DrawImage second_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
+  scoped_refptr<TileTask> second_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      second_draw_image, ImageDecodeController::TracingInfo(), &second_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(second_task);
+  EXPECT_TRUE(first_task.get() != second_task.get());
+
+  DrawImage third_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> third_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      third_draw_image, ImageDecodeController::TracingInfo(), &third_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(third_task.get() == second_task.get());
+
+  TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(second_task.get());
+
+  controller.UnrefImage(second_draw_image);
+  controller.UnrefImage(third_draw_image);
+}
+
+TEST(GpuImageDecodeControllerTest, GetTaskForImageLargerScaleNoReuse) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  sk_sp<SkImage> first_image = CreateImage(100, 100);
+  DrawImage first_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> first_task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      first_draw_image, ImageDecodeController::TracingInfo(), &first_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(first_task);
+
+  DrawImage second_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
+  scoped_refptr<TileTask> second_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      second_draw_image, ImageDecodeController::TracingInfo(), &second_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(second_task);
+  EXPECT_TRUE(first_task.get() != second_task.get());
+
+  DrawImage third_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> third_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      third_draw_image, ImageDecodeController::TracingInfo(), &third_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(third_task.get() == first_task.get());
+
+  TestTileTaskRunner::ProcessTask(first_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(first_task.get());
+  TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(second_task.get());
+
+  controller.UnrefImage(first_draw_image);
+  controller.UnrefImage(second_draw_image);
+  controller.UnrefImage(third_draw_image);
+}
+
+TEST(GpuImageDecodeControllerTest, GetTaskForImageHigherQuality) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkMatrix matrix = CreateMatrix(SkSize::Make(0.4f, 0.4f), is_decomposable);
+
+  sk_sp<SkImage> first_image = CreateImage(100, 100);
+  DrawImage first_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      kLow_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> first_task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      first_draw_image, ImageDecodeController::TracingInfo(), &first_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(first_task);
+
+  TestTileTaskRunner::ProcessTask(first_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(first_task.get());
+
+  controller.UnrefImage(first_draw_image);
+
+  DrawImage second_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      kHigh_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> second_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      second_draw_image, ImageDecodeController::TracingInfo(), &second_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(second_task);
+  EXPECT_TRUE(first_task.get() != second_task.get());
+
+  TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(second_task.get());
+
+  controller.UnrefImage(second_draw_image);
+}
+
 TEST(GpuImageDecodeControllerTest, GetTaskForImageAlreadyDecodedAndLocked) {
   auto context_provider = TestContextProvider::Create();
   context_provider->BindToCurrentThread();
@@ -408,7 +605,7 @@ TEST(GpuImageDecodeControllerTest, GetLargeDecodedImageForDraw) {
   sk_sp<SkImage> image = CreateImage(1, 24000);
   DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
                        quality,
-                       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+                       CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
   scoped_refptr<TileTask> task;
   bool need_unref = controller.GetTaskForImageAndRef(
       draw_image, ImageDecodeController::TracingInfo(), &task);
@@ -446,7 +643,7 @@ TEST(GpuImageDecodeControllerTest, GetDecodedImageForDrawAtRasterDecode) {
   sk_sp<SkImage> image = CreateImage(100, 100);
   DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
                        quality,
-                       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+                       CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
 
   scoped_refptr<TileTask> task;
   bool need_unref = controller.GetTaskForImageAndRef(
@@ -467,6 +664,122 @@ TEST(GpuImageDecodeControllerTest, GetDecodedImageForDrawAtRasterDecode) {
   controller.DrawWithImageFinished(draw_image, decoded_draw_image);
 }
 
+TEST(GpuImageDecodeControllerTest, GetDecodedImageForDrawLargerScale) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  sk_sp<SkImage> image = CreateImage(100, 100);
+  DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
+                       quality,
+                       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      draw_image, ImageDecodeController::TracingInfo(), &task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task);
+
+  TestTileTaskRunner::ProcessTask(task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(task.get());
+
+  DrawImage larger_draw_image(
+      image, SkIRect::MakeWH(image->width(), image->height()), quality,
+      CreateMatrix(SkSize::Make(1.5f, 1.5f), is_decomposable));
+  scoped_refptr<TileTask> larger_task;
+  bool larger_need_unref = controller.GetTaskForImageAndRef(
+      larger_draw_image, ImageDecodeController::TracingInfo(), &larger_task);
+  EXPECT_TRUE(larger_need_unref);
+  EXPECT_TRUE(larger_task);
+
+  TestTileTaskRunner::ProcessTask(larger_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(larger_task.get());
+
+  // Must hold context lock before calling GetDecodedImageForDraw /
+  // DrawWithImageFinished.
+  ContextProvider::ScopedContextLock context_lock(context_provider.get());
+  DecodedDrawImage decoded_draw_image =
+      controller.GetDecodedImageForDraw(draw_image);
+  EXPECT_TRUE(decoded_draw_image.image());
+  EXPECT_TRUE(decoded_draw_image.image()->isTextureBacked());
+  EXPECT_FALSE(decoded_draw_image.is_at_raster_decode());
+  EXPECT_FALSE(controller.DiscardableIsLockedForTesting(draw_image));
+
+  DecodedDrawImage larger_decoded_draw_image =
+      controller.GetDecodedImageForDraw(larger_draw_image);
+  EXPECT_TRUE(larger_decoded_draw_image.image());
+  EXPECT_TRUE(larger_decoded_draw_image.image()->isTextureBacked());
+  EXPECT_FALSE(larger_decoded_draw_image.is_at_raster_decode());
+  EXPECT_FALSE(controller.DiscardableIsLockedForTesting(draw_image));
+
+  EXPECT_FALSE(decoded_draw_image.image() == larger_decoded_draw_image.image());
+
+  controller.DrawWithImageFinished(draw_image, decoded_draw_image);
+  controller.UnrefImage(draw_image);
+  controller.DrawWithImageFinished(larger_draw_image,
+                                   larger_decoded_draw_image);
+  controller.UnrefImage(larger_draw_image);
+}
+
+TEST(GpuImageDecodeControllerTest, GetDecodedImageForDrawHigherQuality) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkMatrix matrix = CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable);
+
+  sk_sp<SkImage> image = CreateImage(100, 100);
+  DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
+                       kLow_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      draw_image, ImageDecodeController::TracingInfo(), &task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(task);
+
+  TestTileTaskRunner::ProcessTask(task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(task.get());
+
+  DrawImage higher_quality_draw_image(
+      image, SkIRect::MakeWH(image->width(), image->height()),
+      kHigh_SkFilterQuality, matrix);
+  scoped_refptr<TileTask> hq_task;
+  bool hq_needs_unref = controller.GetTaskForImageAndRef(
+      higher_quality_draw_image, ImageDecodeController::TracingInfo(),
+      &hq_task);
+  EXPECT_TRUE(hq_needs_unref);
+  EXPECT_TRUE(hq_task);
+
+  TestTileTaskRunner::ProcessTask(hq_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(hq_task.get());
+
+  // Must hold context lock before calling GetDecodedImageForDraw /
+  // DrawWithImageFinished.
+  ContextProvider::ScopedContextLock context_lock(context_provider.get());
+  DecodedDrawImage decoded_draw_image =
+      controller.GetDecodedImageForDraw(draw_image);
+  EXPECT_TRUE(decoded_draw_image.image());
+  EXPECT_TRUE(decoded_draw_image.image()->isTextureBacked());
+  EXPECT_FALSE(decoded_draw_image.is_at_raster_decode());
+  EXPECT_FALSE(controller.DiscardableIsLockedForTesting(draw_image));
+
+  DecodedDrawImage larger_decoded_draw_image =
+      controller.GetDecodedImageForDraw(higher_quality_draw_image);
+  EXPECT_TRUE(larger_decoded_draw_image.image());
+  EXPECT_TRUE(larger_decoded_draw_image.image()->isTextureBacked());
+  EXPECT_FALSE(larger_decoded_draw_image.is_at_raster_decode());
+  EXPECT_FALSE(controller.DiscardableIsLockedForTesting(draw_image));
+
+  EXPECT_FALSE(decoded_draw_image.image() == larger_decoded_draw_image.image());
+
+  controller.DrawWithImageFinished(draw_image, decoded_draw_image);
+  controller.UnrefImage(draw_image);
+  controller.DrawWithImageFinished(higher_quality_draw_image,
+                                   larger_decoded_draw_image);
+  controller.UnrefImage(higher_quality_draw_image);
+}
+
 TEST(GpuImageDecodeControllerTest, AtRasterUsedDirectlyIfSpaceAllows) {
   auto context_provider = TestContextProvider::Create();
   context_provider->BindToCurrentThread();
@@ -559,7 +872,7 @@ TEST(GpuImageDecodeControllerTest,
   sk_sp<SkImage> image = CreateImage(1, 24000);
   DrawImage draw_image(image, SkIRect::MakeWH(image->width(), image->height()),
                        quality,
-                       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+                       CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
 
   // Must hold context lock before calling GetDecodedImageForDraw /
   // DrawWithImageFinished.
@@ -726,5 +1039,108 @@ TEST(GpuImageDecodeControllerTest, ShouldAggressivelyFreeResources) {
   DCHECK_GT(controller.GetBytesUsedForTesting(), 0u);
 }
 
+TEST(GpuImageDecodeControllerTest, OrphanedImagesFreeOnReachingZeroRefs) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  // Create a downscaled image.
+  sk_sp<SkImage> first_image = CreateImage(100, 100);
+  DrawImage first_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> first_task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      first_draw_image, ImageDecodeController::TracingInfo(), &first_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(first_task);
+
+  // The budget should account for exactly one image.
+  EXPECT_EQ(controller.GetBytesUsedForTesting(),
+            controller.GetDrawImageSizeForTesting(first_draw_image));
+
+  // Create a larger version of |first_image|, this should immediately free the
+  // memory used by |first_image| for the smaller scale.
+  DrawImage second_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
+  scoped_refptr<TileTask> second_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      second_draw_image, ImageDecodeController::TracingInfo(), &second_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(second_task);
+  EXPECT_TRUE(first_task.get() != second_task.get());
+
+  TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(second_task.get());
+
+  controller.UnrefImage(second_draw_image);
+
+  // The budget should account for both images one image.
+  EXPECT_EQ(controller.GetBytesUsedForTesting(),
+            controller.GetDrawImageSizeForTesting(second_draw_image) +
+                controller.GetDrawImageSizeForTesting(first_draw_image));
+
+  // Unref the first image, it was orphaned, so it should be immediately
+  // deleted.
+  TestTileTaskRunner::ProcessTask(first_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(first_task.get());
+  controller.UnrefImage(first_draw_image);
+
+  // The budget should account for exactly one image.
+  EXPECT_EQ(controller.GetBytesUsedForTesting(),
+            controller.GetDrawImageSizeForTesting(second_draw_image));
+}
+
+TEST(GpuImageDecodeControllerTest, OrphanedZeroRefImagesImmediatelyDeleted) {
+  auto context_provider = TestContextProvider::Create();
+  context_provider->BindToCurrentThread();
+  TestGpuImageDecodeController controller(context_provider.get());
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  // Create a downscaled image.
+  sk_sp<SkImage> first_image = CreateImage(100, 100);
+  DrawImage first_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
+  scoped_refptr<TileTask> first_task;
+  bool need_unref = controller.GetTaskForImageAndRef(
+      first_draw_image, ImageDecodeController::TracingInfo(), &first_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(first_task);
+
+  TestTileTaskRunner::ProcessTask(first_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(first_task.get());
+  controller.UnrefImage(first_draw_image);
+
+  // The budget should account for exactly one image.
+  EXPECT_EQ(controller.GetBytesUsedForTesting(),
+            controller.GetDrawImageSizeForTesting(first_draw_image));
+
+  // Create a larger version of |first_image|, this should immediately free the
+  // memory used by |first_image| for the smaller scale.
+  DrawImage second_draw_image(
+      first_image, SkIRect::MakeWH(first_image->width(), first_image->height()),
+      quality, CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
+  scoped_refptr<TileTask> second_task;
+  need_unref = controller.GetTaskForImageAndRef(
+      second_draw_image, ImageDecodeController::TracingInfo(), &second_task);
+  EXPECT_TRUE(need_unref);
+  EXPECT_TRUE(second_task);
+  EXPECT_TRUE(first_task.get() != second_task.get());
+
+  TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
+  TestTileTaskRunner::ProcessTask(second_task.get());
+
+  controller.UnrefImage(second_draw_image);
+
+  // The budget should account for exactly one image.
+  EXPECT_EQ(controller.GetBytesUsedForTesting(),
+            controller.GetDrawImageSizeForTesting(second_draw_image));
+}
+
 }  // namespace
 }  // namespace cc