Plumb PinchVirtualViewport layers into CC.

cc/trees/layer_tree_host.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_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <list>
 #include <vector>
@@ skipping 183 matching lines @@
   bool CommitRequested() const;
 
   void SetNextCommitWaitsForActivation();
 
   void SetAnimationEvents(scoped_ptr<AnimationEventsVector> events,
                           base::Time wall_clock_time);
 
   void SetRootLayer(scoped_refptr<Layer> root_layer);
   Layer* root_layer() { return root_layer_.get(); }
   const Layer* root_layer() const { return root_layer_.get(); }
+  void RegisterViewportLayers(
+      scoped_refptr<Layer> page_scale_layer,
+      scoped_refptr<Layer> inner_viewport_scroll_layer,
+      scoped_refptr<Layer> outer_viewport_scroll_layer);
 
   const LayerTreeSettings& settings() const { return settings_; }
 
   void SetDebugState(const LayerTreeDebugState& debug_state);
   const LayerTreeDebugState& debug_state() const { return debug_state_; }
 
   void SetViewportSize(gfx::Size device_viewport_size);
   void SetOverdrawBottomHeight(float overdraw_bottom_height);
 
   gfx::Size device_viewport_size() const { return device_viewport_size_; }
@@ skipping 198 matching lines @@
           total_num_cc_layers_can_use_lcd_text(0),
           total_num_cc_layers_will_use_lcd_text(0) {}
 
     int64 total_num_cc_layers;
     int64 total_num_cc_layers_can_use_lcd_text;
     int64 total_num_cc_layers_will_use_lcd_text;
   };
   LCDTextMetrics lcd_text_metrics_;
   int tree_id_;
 
+  scoped_refptr<Layer> page_scale_layer_;
+  scoped_refptr<Layer> inner_viewport_scroll_layer_;
+  scoped_refptr<Layer> outer_viewport_scroll_layer_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_