Add display list fallback reason histograms for 2D canvas

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/canvas2d/CanvasRenderingContext2D.h"
 
 #include "core/fetch/MemoryCache.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/html/HTMLCanvasElement.h"
@@ skipping 18 matching lines @@
 
 enum BitmapOpacity {
     OpaqueBitmap,
     TransparentBitmap
 };
 
 class FakeImageSource : public CanvasImageSource {
 public:
     FakeImageSource(IntSize, BitmapOpacity);
 
-    PassRefPtr<Image> getSourceImageForCanvas(SourceImageStatus*, AccelerationHint) const override;
+    PassRefPtr<Image> getSourceImageForCanvas(SourceImageStatus*, AccelerationHint, SnapshotReason) const override;
 
     bool wouldTaintOrigin(SecurityOrigin* destinationSecurityOrigin) const override { return false; }
     FloatSize elementSize() const override { return FloatSize(m_size); }
     bool isOpaque() const override { return m_isOpaque; }
 
     ~FakeImageSource() override { }
 
 private:
     IntSize m_size;
     RefPtr<Image> m_image;
     bool m_isOpaque;
 };
 
 FakeImageSource::FakeImageSource(IntSize size, BitmapOpacity opacity)
     : m_size(size)
     , m_isOpaque(opacity == OpaqueBitmap)
 {
     SkAutoTUnref<SkSurface> surface(SkSurface::NewRasterN32Premul(m_size.width(), m_size.height()));
     surface->getCanvas()->clear(opacity == OpaqueBitmap ? SK_ColorWHITE : SK_ColorTRANSPARENT);
     RefPtr<SkImage> image = adoptRef(surface->newImageSnapshot());
     m_image = StaticBitmapImage::create(image);
 }
 
-PassRefPtr<Image> FakeImageSource::getSourceImageForCanvas(SourceImageStatus* status, AccelerationHint) const
+PassRefPtr<Image> FakeImageSource::getSourceImageForCanvas(SourceImageStatus* status, AccelerationHint, SnapshotReason) const
 {
     if (status)
         *status = NormalSourceImageStatus;
     return m_image;
 }
 
 //============================================================================
 
 class CanvasRenderingContext2DTest : public ::testing::Test {
 protected:
@@ skipping 635 matching lines @@
     canvasElement().setSize(IntSize(20, 20));
     Mock::VerifyAndClearExpectations(fakeAccelerateSurfacePtr);
     EXPECT_EQ(400, getGlobalGPUMemoryUsage());
 
     // Tear down the second image buffer
     imageBuffer2.clear();
     EXPECT_EQ(0, getGlobalGPUMemoryUsage());
 }
 
 } // namespace blink