Reland: Make 2D canvas disable gpu acceleration when getImageData is called

third_party/WebKit/Source/platform/graphics/ImageBuffer.h

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 74 matching lines @@
     const IntSize& size() const { return m_surface->size(); }
     bool isAccelerated() const { return m_surface->isAccelerated(); }
     bool isRecording() const { return m_surface->isRecording(); }
     void setHasExpensiveOp() { m_surface->setHasExpensiveOp(); }
     bool isExpensiveToPaint() const { return m_surface->isExpensiveToPaint(); }
     void prepareSurfaceForPaintingIfNeeded() { m_surface->prepareSurfaceForPaintingIfNeeded(); }
     bool isSurfaceValid() const;
     bool restoreSurface() const;
     void didDraw(const FloatRect&) const;
     bool wasDrawnToAfterSnapshot() const { return m_snapshotState == DrawnToAfterSnapshot; }
+    void didDisableAcceleration() const;
 
     void setFilterQuality(SkFilterQuality filterQuality) { m_surface->setFilterQuality(filterQuality); }
     void setIsHidden(bool hidden) { m_surface->setIsHidden(hidden); }
 
     // Called by subclasses of ImageBufferSurface to install a new canvas object.
     // Virtual for mocking
     virtual void resetCanvas(SkCanvas*) const;
 
     SkCanvas* canvas() const;
     void disableDeferral(DisableDeferralReason) const;
@@ skipping 68 matching lines @@
     int height() const { return m_size.height(); }
     int width() const { return m_size.width(); }
 
     const unsigned char* m_data;
     const IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // ImageBuffer_h