Revamp OffscreenCanvas commit flow

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 1379 matching lines @@
     return m_context->getControlAndIdIfHitRegionExists(location);
   return HitTestCanvasResult::create(String(), nullptr);
 }
 
 String HTMLCanvasElement::getIdFromControl(const Element* element) {
   if (m_context)
     return m_context->getIdFromControl(element);
   return String();
 }
 
-bool HTMLCanvasElement::createSurfaceLayer() {
+void HTMLCanvasElement::createLayer() {
   DCHECK(!m_surfaceLayerBridge);
   mojom::blink::OffscreenCanvasSurfacePtr service;
   Platform::current()->interfaceProvider()->getInterface(
       mojo::GetProxy(&service));
   m_surfaceLayerBridge =
-      WTF::wrapUnique(new CanvasSurfaceLayerBridge(std::move(service)));
-  return m_surfaceLayerBridge->createSurfaceLayer(this->width(),
-                                                  this->height());
+      WTF::wrapUnique(new CanvasSurfaceLayerBridge(std::move(service), this));
+  // Creates a placeholder layer first before Surface is created.
+  m_surfaceLayerBridge->createSolidColorLayer();
+}
+
+void HTMLCanvasElement::OnWebLayerReplaced() {
+  setNeedsCompositingUpdate();
 }
 
 }  // namespace blink