cc: Main thread skip single layers instead of subtrees

cc/layers/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_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 80 matching lines @@
   int id() const { return layer_id_; }
 
   // Interactions with attached animations.
   gfx::ScrollOffset ScrollOffsetForAnimation() const;
   void OnFilterAnimated(const FilterOperations& filters);
   void OnOpacityAnimated(float opacity);
   void OnTransformAnimated(const gfx::Transform& transform);
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset);
   void OnTransformIsPotentiallyAnimatingChanged(bool is_animating);
   bool IsActive() const;
+  bool OpacityCanAnimateOnImplThread() const { return false; }
 
   // Tree structure.
   LayerImpl* parent() { return parent_; }
   LayerImplList& children() { return children_; }
   LayerImpl* child_at(size_t index) const { return children_[index]; }
   void AddChild(scoped_ptr<LayerImpl> child);
   scoped_ptr<LayerImpl> RemoveChildForTesting(LayerImpl* child);
   void SetParent(LayerImpl* parent);
 
   void SetScrollParent(LayerImpl* parent);
@@ skipping 655 matching lines @@
   bool layer_or_descendant_is_drawn_;
   // If true, the layer or one of its descendants has a touch handler.
   bool layer_or_descendant_has_touch_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_