cc: Add receiver for CompositorFrameAck in LayerTreeHostImpl and forward it to the renderer.

cc/renderer.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 CC_RENDERER_H_
 #define CC_RENDERER_H_
 
 #include "base/basictypes.h"
 #include "cc/cc_export.h"
 #include "cc/layer_tree_host.h"
 #include "cc/managed_memory_policy.h"
 #include "cc/render_pass.h"
 
 namespace cc {
 
+class CompositorFrameAck;
 class ScopedResource;
 
 class CC_EXPORT RendererClient {
 public:
     virtual const gfx::Size& deviceViewportSize() const = 0;
     virtual const LayerTreeSettings& settings() const = 0;
     virtual void didLoseContext() = 0;
     virtual void onSwapBuffersComplete() = 0;
     virtual void setFullRootLayerDamage() = 0;
     virtual void setManagedMemoryPolicy(const ManagedMemoryPolicy& policy) = 0;
@@ skipping 16 matching lines @@
 
     virtual const RendererCapabilities& capabilities() const = 0;
 
     const LayerTreeSettings& settings() const { return m_client->settings(); }
 
     gfx::Size viewportSize() { return m_client->deviceViewportSize(); }
     int viewportWidth() { return viewportSize().width(); }
     int viewportHeight() { return viewportSize().height(); }
 
     virtual void viewportChanged() { }
+    virtual void receiveCompositorFrameAck(const CompositorFrameAck&) { }
 
     virtual void decideRenderPassAllocationsForFrame(const RenderPassList&) { }
     virtual bool haveCachedResourcesForRenderPassId(RenderPass::Id) const;
 
     // This passes ownership of the render passes to the renderer. It should
     // consume them, and empty the list and hash map.
     virtual void drawFrame(RenderPassList&, RenderPassIdHashMap&) = 0;
 
     // waits for rendering to finish
     virtual void finish() = 0;
@@ skipping 17 matching lines @@
     }
 
     RendererClient* m_client;
 
     DISALLOW_COPY_AND_ASSIGN(Renderer);
 };
 
 }
 
 #endif  // CC_RENDERER_H_