Make OffscreenCanvas resizable

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 1386 matching lines @@
   return String();
 }
 
 void HTMLCanvasElement::createLayer() {
   DCHECK(!m_surfaceLayerBridge);
   m_surfaceLayerBridge = WTF::wrapUnique(new CanvasSurfaceLayerBridge(this));
   // Creates a placeholder layer first before Surface is created.
   m_surfaceLayerBridge->createSolidColorLayer();
 }
 
-void HTMLCanvasElement::OnWebLayerReplaced() {
+void HTMLCanvasElement::OnWebLayerReplaced(int width, int height) {
+  if (width != sourceWidth() || height != sourceHeight()) {
+    setSize(IntSize(width, height));
+  }
   setNeedsCompositingUpdate();
 }
 
 }  // namespace blink