cc: Avoid updating animations in the background without an active tree

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 134 matching lines @@
   void StartCommitOnImplThread(
       CompletionEvent* completion,
       ResourceUpdateQueue* queue,
       scoped_refptr<cc::ContextProvider> offscreen_context_provider);
   void BeginFrameAbortedByMainThreadOnImplThread(bool did_handle);
   void RequestReadbackOnImplThread(ReadbackRequest* request);
   void FinishAllRenderingOnImplThread(CompletionEvent* completion);
   void InitializeImplOnImplThread(CompletionEvent* completion);
   void SetLayerTreeHostClientReadyOnImplThread();
   void SetVisibleOnImplThread(CompletionEvent* completion, bool visible);
+  void UpdateBackgroundAnimateTicking();
   void HasInitializedOutputSurfaceOnImplThread(
       CompletionEvent* completion,
       bool* has_initialized_output_surface);
   void InitializeOutputSurfaceOnImplThread(
       CompletionEvent* completion,
       scoped_ptr<OutputSurface> output_surface,
       scoped_refptr<ContextProvider> offscreen_context_provider,
       bool* success,
       RendererCapabilities* capabilities);
   void FinishGLOnImplThread(CompletionEvent* completion);
@@ skipping 95 matching lines @@
   // activation_duration_history_.
   base::TimeTicks begin_frame_sent_to_main_thread_time_;
   base::TimeTicks commit_complete_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadProxy);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_THREAD_PROXY_H_