Revert of Make 2D canvas disable gpu acceleration when getImageData is called

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

 /*
  * Copyright (C) 2004, 2006, 2007 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 300 matching lines @@
     if (ro && (!m_context || !m_context->isAccelerated())) {
         LayoutRect mappedDirtyRect(enclosingIntRect(mapRect(m_dirtyRect, srcRect, FloatRect(ro->contentBoxRect()))));
         // For querying PaintLayer::compositingState()
         // FIXME: is this invalidation using the correct compositing state?
         DisableCompositingQueryAsserts disabler;
         ro->invalidatePaintRectangle(mappedDirtyRect);
     }
     m_dirtyRect = FloatRect();
 }
 
-void HTMLCanvasElement::didDisableAcceleration()
-{
-    // We must force a paint invalidation on the canvas even if it's
-    // content did not change because it layer was destroyed.
-    didDraw(FloatRect(0, 0, size().width(), size().height()));
-}
-
 void HTMLCanvasElement::restoreCanvasMatrixClipStack(SkCanvas* canvas) const
 {
     if (m_context)
         m_context->restoreCanvasMatrixClipStack(canvas);
 }
 
 void HTMLCanvasElement::doDeferredPaintInvalidation()
 {
     DCHECK(!m_dirtyRect.isEmpty());
     if (!m_context->is2d()) {
@@ skipping 856 matching lines @@
 
 bool HTMLCanvasElement::createSurfaceLayer()
 {
     DCHECK(!m_surfaceLayerBridge);
     std::unique_ptr<CanvasSurfaceLayerBridgeClient> bridgeClient = wrapUnique(new CanvasSurfaceLayerBridgeClientImpl());
     m_surfaceLayerBridge = wrapUnique(new CanvasSurfaceLayerBridge(std::move(bridgeClient)));
     return m_surfaceLayerBridge->createSurfaceLayer(this->width(), this->height());
 }
 
 } // namespace blink