Add CCDelegatingRenderer, and corresponding IPCs

cc/CCRenderer.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CCRenderer_h
 #define CCRenderer_h
 
 #include "base/basictypes.h"
 #include "CCLayerTreeHost.h"
 #include "CCRenderPass.h"
 #include "FloatQuad.h"
 #include "IntRect.h"
 #include <wtf/PassRefPtr.h>
 
+namespace WebKit {
+struct WebCompositorFrameAck;
+}
+
 namespace cc {
 
 class CCScopedTexture;
 
 class CCRendererClient {
 public:
     virtual const IntSize& deviceViewportSize() const = 0;
     virtual const CCLayerTreeSettings& settings() const = 0;
     virtual void didLoseContext() = 0;
     virtual void onSwapBuffersComplete() = 0;
@@ skipping 35 matching lines @@
 
     virtual void doNoOp() { }
     // puts backbuffer onscreen
     virtual bool swapBuffers() = 0;
 
     virtual void getFramebufferPixels(void *pixels, const IntRect&) = 0;
 
     virtual bool isContextLost();
 
     virtual void setVisible(bool) = 0;
+    virtual void onSendFrameToParentCompositorAck(const WebKit::WebCompositorFrameAck&) { }
 
 protected:
     explicit CCRenderer(CCRendererClient* client)
         : m_client(client)
     {
     }
 
     CCRendererClient* m_client;
 
     DISALLOW_COPY_AND_ASSIGN(CCRenderer);
 };
 
 }
 
 #endif // CCRenderer_h