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..a7500db150270eb59839e6e88ac111cdc160bf10 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"
@@ -28,40 +27,39 @@ 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);
     virtual ~RecordingImageBufferSurface();
 
     // Implementation of ImageBufferSurface interfaces
-    virtual SkCanvas* canvas() const override;
-    virtual PassRefPtr<SkPicture> getPicture() override;
-    virtual void willDrawVideo() override;
-    virtual void didDraw() override;
-    virtual bool isValid() const override { return true; }
-    virtual bool isRecording() const override { return !m_fallbackSurface; }
-    virtual void willAccessPixels() override;
-    virtual void finalizeFrame(const FloatRect&) override;
-    virtual void setImageBuffer(ImageBuffer*) override;
-    virtual PassRefPtr<SkImage> newImageSnapshot() const override;
-    virtual bool needsClipTracking() const override { return !m_fallbackSurface; }
+    SkCanvas* canvas() const override;
+    PassRefPtr<SkPicture> getPicture() override;
+    void willDrawVideo() override;
+    void didDraw() override;
+    bool isValid() const override { return true; }
+    bool isRecording() const override { return !m_fallbackSurface; }
+    void willAccessPixels() override;
+    void willOverwriteCanvas() override;
+    void finalizeFrame(const FloatRect&) override;
+    void setImageBuffer(ImageBuffer*) override;
+    PassRefPtr<SkImage> newImageSnapshot() const override;
+    bool needsClipTracking() const override { return !m_fallbackSurface; }
     void draw(GraphicsContext*, const FloatRect& destRect, const FloatRect& srcRect, SkXfermode::Mode, bool needsCopy) override;
 
     // Passthroughs to fallback surface
-    virtual const SkBitmap& bitmap() override;
-    virtual bool restore() override;
-    virtual WebLayer* layer() const override;
-    virtual bool isAccelerated() const override;
-    virtual Platform3DObject getBackingTexture() const override;
-    virtual bool cachedBitmapEnabled() const override;
-    virtual const SkBitmap& cachedBitmap() const override;
-    virtual void invalidateCachedBitmap() override;
-    virtual void updateCachedBitmapIfNeeded() override;
-    virtual void setIsHidden(bool) override;
+    const SkBitmap& bitmap() override;
+    bool restore() override;
+    WebLayer* layer() const override;
+    bool isAccelerated() const override;
+    Platform3DObject getBackingTexture() const override;
+    bool cachedBitmapEnabled() const override;
+    const SkBitmap& cachedBitmap() const override;
+    void invalidateCachedBitmap() override;
+    void updateCachedBitmapIfNeeded() override;
+    void setIsHidden(bool) override;
 
-    // Implementation of GraphicsContextClient
-    virtual void willOverwriteCanvas() override;
 private:
     friend class ::RecordingImageBufferSurfaceTest; // for unit testing
     void fallBackToRasterCanvas();