We don't want to tick animation controllers for non-active layers

cc/layer_impl.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_LAYER_IMPL_H_
 #define CC_LAYER_IMPL_H_
 
 #include <string>
 
 #include "base/logging.h"
@@ skipping 42 matching lines @@
         return make_scoped_ptr(new LayerImpl(treeImpl, id));
     }
 
     virtual ~LayerImpl();
 
     int id() const;
 
     // LayerAnimationValueObserver implementation.
     virtual void OnOpacityAnimated(float) OVERRIDE;
     virtual void OnTransformAnimated(const gfx::Transform&) OVERRIDE;
+    virtual bool IsActive() const OVERRIDE;
 
     // Tree structure.
     LayerImpl* parent() { return m_parent; }
     const LayerImpl* parent() const { return m_parent; }
     const LayerList& children() const { return m_children; }
     void addChild(scoped_ptr<LayerImpl>);
     scoped_ptr<LayerImpl> removeChild(LayerImpl* child);
     void removeAllChildren();
 
     void setMaskLayer(scoped_ptr<LayerImpl>);
@@ skipping 325 matching lines @@
     // Group of properties that need to be computed based on the layer tree
     // hierarchy before layers can be drawn.
     DrawProperties<LayerImpl, RenderSurfaceImpl> m_drawProperties;
 
     DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }
 
 #endif  // CC_LAYER_IMPL_H_