Make 2D canvas disable gpu acceleration when getImageData is called

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp

Index: third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp
diff --git a/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp b/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp
index a33dbafaf9f050c81c5701da5a5fabc42039a45d..a6a6b8446c6dcaa67b5cfb92ea5258808e6e799d 100644
--- a/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp
+++ b/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DTest.cpp
@@ -16,10 +16,13 @@
 #include "modules/canvas2d/CanvasGradient.h"
 #include "modules/canvas2d/CanvasPattern.h"
 #include "modules/webgl/WebGLRenderingContext.h"
+#include "platform/graphics/Canvas2DImageBufferSurface.h"
 #include "platform/graphics/ExpensiveCanvasHeuristicParameters.h"
 #include "platform/graphics/RecordingImageBufferSurface.h"
 #include "platform/graphics/StaticBitmapImage.h"
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
+#include "platform/graphics/test/FakeGLES2Interface.h"
+#include "platform/graphics/test/FakeWebGraphicsContext3DProvider.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkSurface.h"
@@ -88,6 +91,7 @@ protected:
     void createContext(OpacityMode);
     void TearDown();
     void unrefCanvas();
+    PassRefPtr<Canvas2DLayerBridge> makeBridge(std::unique_ptr<FakeWebGraphicsContext3DProvider>, const IntSize&, Canvas2DLayerBridge::AccelerationMode);
 
 private:
     std::unique_ptr<DummyPageHolder> m_dummyPageHolder;
@@ -178,6 +182,11 @@ void CanvasRenderingContext2DTest::TearDown()
     replaceMemoryCacheForTesting(m_globalMemoryCache.release());
 }
 
+PassRefPtr<Canvas2DLayerBridge> CanvasRenderingContext2DTest::makeBridge(std::unique_ptr<FakeWebGraphicsContext3DProvider> provider, const IntSize& size, Canvas2DLayerBridge::AccelerationMode accelerationMode)
+{
+    return adoptRef(new Canvas2DLayerBridge(std::move(provider), size, 0, NonOpaque, accelerationMode));
+}
+
 //============================================================================
 
 class FakeAcceleratedImageBufferSurfaceForTesting : public UnacceleratedImageBufferSurface {
@@ -751,4 +760,30 @@ TEST_F(CanvasRenderingContext2DTest, ContextDisposedBeforeCanvas)
     // Passes by not crashing later during teardown
 }
 
+TEST_F(CanvasRenderingContext2DTest, GetImageDataDisablesAcceleration)
+{
+    createContext(NonOpaque);
+    FakeGLES2Interface gl;
+    std::unique_ptr<FakeWebGraphicsContext3DProvider> contextProvider(new FakeWebGraphicsContext3DProvider(&gl));
+    IntSize size(300, 300);
+    RefPtr<Canvas2DLayerBridge> bridge = makeBridge(std::move(contextProvider), size, Canvas2DLayerBridge::EnableAcceleration);
+    std::unique_ptr<Canvas2DImageBufferSurface> surface(new Canvas2DImageBufferSurface(bridge, size, NonOpaque));
+    canvasElement().createImageBufferUsingSurfaceForTesting(std::move(surface));
+
+    EXPECT_TRUE(bridge->isAccelerated());
+    EXPECT_EQ(1u, getGlobalAcceleratedImageBufferCount());
+    EXPECT_EQ(720000, getGlobalGPUMemoryUsage());
+
+    bool savedValue = RuntimeEnabledFeatures::canvas2dFixedRenderingModeEnabled();
+    RuntimeEnabledFeatures::setCanvas2dFixedRenderingModeEnabled(false);

[xlai (Olivia), 2016/06/23 19:55:02]

Nits: Why don't you set the Canvas2dFixedRenderingModeEnabled=false at the
beginning of the test (before 773)? In theory, as long as you don't call
getImageData, the ForceDisableAcceleration should not happen.

[Justin Novosad, 2016/06/23 21:02:09]

Done.

+    TrackExceptionState exceptionState;
+    context2d()->getImageData(0, 0, 1, 1, exceptionState);
+    RuntimeEnabledFeatures::setCanvas2dFixedRenderingModeEnabled(savedValue);
+
+    EXPECT_FALSE(exceptionState.hadException());
+    EXPECT_FALSE(bridge->isAccelerated());
+    EXPECT_EQ(0u, getGlobalAcceleratedImageBufferCount());
+    EXPECT_EQ(0, getGlobalGPUMemoryUsage());
+}
+
 } // namespace blink