Only do full tree sync if tree is actually changed, otherwise just push properties

cc/layer.h

 // Copyright 2010 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_H_
 #define CC_LAYER_H_
 
 #include <public/WebFilterOperations.h>
 #include <string>
 #include <vector>
@@ skipping 291 matching lines @@
     gfx::Rect layerRectToContentRect(const gfx::RectF& layerRect) const;
 
 protected:
     friend class LayerImpl;
     friend class TreeSynchronizer;
     virtual ~Layer();
 
     Layer();
 
     void setNeedsCommit();
+    void setNeedsFullTreeSync();
 
     // This flag is set when layer need repainting/updating.
     bool m_needsDisplay;
 
     // Tracks whether this layer may have changed stacking order with its siblings.
     bool m_stackingOrderChanged;
 
     // The update rect is the region of the compositor resource that was actually updated by the compositor.
     // For layers that may do updating outside the compositor's control (i.e. plugin layers), this information
     // is not available and the update rect will remain empty.
@@ skipping 100 matching lines @@
 
     WebKit::WebAnimationDelegate* m_layerAnimationDelegate;
     WebKit::WebLayerScrollClient* m_layerScrollClient;
 };
 
 void sortLayers(std::vector<scoped_refptr<Layer> >::iterator, std::vector<scoped_refptr<Layer> >::iterator, void*);
 
 }  // namespace cc
 
 #endif  // CC_LAYER_H_