cc: Commit directly to active tree when using single thread.

cc/trees/thread_proxy.h

 // Copyright 2011 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_TREES_THREAD_PROXY_H_
 #define CC_TREES_THREAD_PROXY_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 136 matching lines @@
     base::WeakPtrFactory<ThreadProxy> weak_factory;
   };
 
   const MainThreadOnly& main() const;
   const MainThreadOrBlockedMainThread& blocked_main() const;
   const CompositorThreadOnly& impl() const;
 
   // Proxy implementation
   void FinishAllRendering() override;
   bool IsStarted() const override;
+  bool CommitToActiveTree() const override;
   void SetOutputSurface(scoped_ptr<OutputSurface>) override;
   void SetLayerTreeHostClientReady() override;
   void SetVisible(bool visible) override;
   void SetThrottleFrameProduction(bool throttle) override;
   const RendererCapabilities& GetRendererCapabilities() const override;
   void SetNeedsAnimate() override;
   void SetNeedsUpdateLayers() override;
   void SetNeedsCommit() override;
   void SetNeedsRedraw(const gfx::Rect& damage_rect) override;
   void SetNextCommitWaitsForActivation() override;
@@ skipping 134 matching lines @@
 
   base::WeakPtr<ThreadProxy> main_thread_weak_ptr_;
   base::WeakPtr<ThreadProxy> impl_thread_weak_ptr_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadProxy);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_THREAD_PROXY_H_