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

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * 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 157 matching lines @@
     bool wouldTaintOrigin(SecurityOrigin*) const override;
     FloatSize elementSize(const FloatSize&) const override;
     bool isCanvasElement() const override { return true; }
     bool isOpaque() const override;
     int sourceWidth() override { return m_size.width(); }
     int sourceHeight() override { return m_size.height(); }
 
     // ImageBufferClient implementation
     void notifySurfaceInvalid() override;
     bool isDirty() override { return !m_dirtyRect.isEmpty(); }
+    void didDisableAcceleration() override;
     void didFinalizeFrame() override;
     void restoreCanvasMatrixClipStack(SkCanvas*) const override;
 
     void doDeferredPaintInvalidation();
 
     // ImageBitmapSource implementation
     IntSize bitmapSourceSize() const override;
     ScriptPromise createImageBitmap(ScriptState*, EventTarget&, int sx, int sy, int sw, int sh, const ImageBitmapOptions&, ExceptionState&) override;
 
     DECLARE_VIRTUAL_TRACE();
@@ skipping 71 matching lines @@
 
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 
     // Used for OffscreenCanvas that controls this HTML canvas element
     std::unique_ptr<CanvasSurfaceLayerBridge> m_surfaceLayerBridge;
 };
 
 } // namespace blink
 
 #endif // HTMLCanvasElement_h