cc: Send shared variables between main and impl side using the channel

cc/trees/threaded_channel.h

 // Copyright 2015 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_THREADED_CHANNEL_H_
 #define CC_TREES_THREADED_CHANNEL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
@@ skipping 78 matching lines @@
   void SetNeedsRedrawOnImpl(const gfx::Rect& damage_rect) override;
   void SetVisibleOnImpl(bool visible) override;
 
   // Blocking calls to ProxyImpl
   void FinishAllRenderingOnImpl(CompletionEvent* completion) override;
   void ReleaseOutputSurfaceOnImpl(CompletionEvent* completion) override;
   void FinishGLOnImpl(CompletionEvent* completion) override;
   void MainFrameWillHappenOnImplForTesting(
       CompletionEvent* completion,
       bool* main_frame_will_happen) override;
-  void StartCommitOnImpl(CompletionEvent* completion) override;
+  void StartCommitOnImpl(CompletionEvent* completion,
+                         LayerTreeHost* layer_tree_host,
+                         bool hold_commit_for_activation) override;
+  void InitializeImplOnImpl(CompletionEvent* completion,
+                            LayerTreeHost* layer_tree_host) override;
+  void LayerTreeHostClosedOnImpl(CompletionEvent* completion) override;
 
   // ChannelImpl Implementation
   void DidCompleteSwapBuffers() override;
   void SetRendererCapabilitiesMainCopy(
       const RendererCapabilities& capabilities) override;
   void BeginMainFrameNotExpectedSoon() override;
   void DidCommitAndDrawFrame() override;
   void SetAnimationEvents(scoped_ptr<AnimationEventsVector> queue) override;
   void DidLoseOutputSurface() override;
   void RequestNewOutputSurface() override;
@@ skipping 30 matching lines @@
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 
   scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadedChannel);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_THREADED_CHANNEL_H_