cc: Add id->LayerImpl map to LayerTreeImpl

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 <public/WebFilterOperations.h>
 #include <string>
 
@@ skipping 275 matching lines @@
 
     // Get the color and size of the layer's debug border.
     virtual void getDebugBorderProperties(SkColor*, float* width) const;
 
     void appendDebugBorderQuad(QuadSink&, const SharedQuadState*, AppendQuadsData&) const;
 
     virtual void dumpLayerProperties(std::string*, int indent) const;
     static std::string indentString(int indent);
 
 private:
+    scoped_ptr<LayerImpl> takeMaskLayer();
+    scoped_ptr<LayerImpl> takeReplicaLayer();
+
     void setParent(LayerImpl* parent) { m_parent = parent; }
     friend class TreeSynchronizer;
     void clearChildList(); // Warning: This does not preserve tree structure invariants and so is only exposed to the tree synchronizer.
 
     void noteLayerSurfacePropertyChanged();
     void noteLayerPropertyChanged();
     void noteLayerPropertyChangedForSubtree();
 
     // Note carefully this does not affect the current layer.
     void noteLayerPropertyChangedForDescendants();
@@ skipping 92 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_