Move overdraw tracking code from GraphicsContext to CanvasRenderingContext2D

Source/platform/graphics/RecordingImageBufferSurface.h

Index: Source/platform/graphics/RecordingImageBufferSurface.h
diff --git a/Source/platform/graphics/RecordingImageBufferSurface.h b/Source/platform/graphics/RecordingImageBufferSurface.h
index 558f3aef94f6877caacacac160a81bfd0b49f8cd..0cafa66118fa9cc334e6dd79d185ccab2bb35873 100644
--- a/Source/platform/graphics/RecordingImageBufferSurface.h
+++ b/Source/platform/graphics/RecordingImageBufferSurface.h
@@ -6,7 +6,6 @@
 #define RecordingImageBufferSurface_h
 
 #include "platform/graphics/GraphicsContext.h"
-#include "platform/graphics/GraphicsContextClient.h"
 #include "platform/graphics/ImageBufferSurface.h"
 #include "public/platform/WebThread.h"
 #include "third_party/skia/include/core/SkCanvas.h"
@@ -28,7 +27,7 @@ public:
     virtual ~RecordingImageBufferFallbackSurfaceFactory() { }
 };
 
-class PLATFORM_EXPORT RecordingImageBufferSurface : public ImageBufferSurface, public GraphicsContextClient {
+class PLATFORM_EXPORT RecordingImageBufferSurface : public ImageBufferSurface {
     WTF_MAKE_NONCOPYABLE(RecordingImageBufferSurface); WTF_MAKE_FAST_ALLOCATED;
 public:
     RecordingImageBufferSurface(const IntSize&, PassOwnPtr<RecordingImageBufferFallbackSurfaceFactory> fallbackFactory, OpacityMode = NonOpaque);
@@ -42,6 +41,7 @@ public:
     virtual bool isValid() const override { return true; }
     virtual bool isRecording() const override { return !m_fallbackSurface; }
     virtual void willAccessPixels() override;
+    virtual void willOverwriteCanvas() override;

[dshwang, 2015/02/06 19:10:37]

after c++11, code style is changed to using only 'override' for subclass; void
willOverwriteCanvas() override;
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Inheritance

[Justin Novosad, 2015/02/06 19:37:31]

Acknowledged.

     virtual void finalizeFrame(const FloatRect&) override;
     virtual void setImageBuffer(ImageBuffer*) override;
     virtual PassRefPtr<SkImage> newImageSnapshot() const override;
@@ -60,8 +60,6 @@ public:
     virtual void updateCachedBitmapIfNeeded() override;
     virtual void setIsHidden(bool) override;
 
-    // Implementation of GraphicsContextClient
-    virtual void willOverwriteCanvas() override;
 private:
     friend class ::RecordingImageBufferSurfaceTest; // for unit testing
     void fallBackToRasterCanvas();