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

cc/trees/single_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_SINGLE_THREAD_PROXY_H_
 #define CC_TREES_SINGLE_THREAD_PROXY_H_
 
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 75 matching lines @@
   void DoCommit(scoped_ptr<ResourceUpdateQueue> queue);
   bool DoComposite(
       scoped_refptr<cc::ContextProvider> offscreen_context_provider,
       base::TimeTicks frame_begin_time,
       gfx::Rect device_viewport_damage_rect,
       bool for_readback,
       LayerTreeHostImpl::FrameData* frame);
   void DidSwapFrame();
 
   bool ShouldComposite() const;
+  void UpdateBackgroundAnimateTicking();
 
   // Accessed on main thread only.
   LayerTreeHost* layer_tree_host_;
   bool created_offscreen_context_provider_;
 
   // Holds the first output surface passed from Start. Should not be used for
   // anything else.
   scoped_ptr<OutputSurface> first_output_surface_;
 
   // Used on the Thread, but checked on main thread during
@@ skipping 65 matching lines @@
  private:
   DebugScopedSetImplThread impl_thread_;
   DebugScopedSetMainThreadBlocked main_thread_blocked_;
 
   DISALLOW_COPY_AND_ASSIGN(DebugScopedSetImplThreadAndMainThreadBlocked);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_SINGLE_THREAD_PROXY_H_