Make 2D canvas disable gpu acceleration when getImageData is called

third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.h

 /*
  * Copyright (C) 2012 Google Inc. 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 175 matching lines @@
     };
 
     Canvas2DLayerBridge(PassOwnPtr<WebGraphicsContext3DProvider>, const IntSize&, int msaaSampleCount, OpacityMode, AccelerationMode);
     gpu::gles2::GLES2Interface* contextGL();
     void startRecording();
     void skipQueuedDrawCommands();
     void flushRecordingOnly();
     void unregisterTaskObserver();
     void reportSurfaceCreationFailure();
 
+    void disableAcceleration();
+
     // WebThread::TaskOberver implementation
     void willProcessTask() override;
     void didProcessTask() override;
 
     SkSurface* getOrCreateSurface(AccelerationHint = PreferAcceleration);
     bool shouldAccelerate(AccelerationHint) const;
 
     // Returns the GL filter associated with |m_filterQuality|.
     GLenum getGLFilter();
 
@@ skipping 71 matching lines @@
     // Each element in this vector represents an IOSurface backed texture that
     // is ready to be reused.
     // Elements in this vector can safely be purged in low memory conditions.
     Vector<ImageInfo> m_imageInfoCache;
 #endif // USE_IOSURFACE_FOR_2D_CANVAS
 };
 
 } // namespace blink
 
 #endif