Properly initialize top controls content offset on LayerTreeHost.

cc/trees/layer_tree_impl.h

 // Copyright 2012 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_IMPL_H_
 #define CC_TREES_LAYER_TREE_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 277 matching lines @@
   // the viewport.
   void GetViewportSelection(ViewportSelectionBound* start,
                             ViewportSelectionBound* end);
 
   void RegisterPictureLayerImpl(PictureLayerImpl* layer);
   void UnregisterPictureLayerImpl(PictureLayerImpl* layer);
 
   void set_top_controls_layout_height(float height) {
     top_controls_layout_height_ = height;
   }
-  void set_top_controls_top_offset(float offset) {
-    top_controls_top_offset_ = offset;
+  void set_top_controls_content_offset(float offset) {
+    top_controls_content_offset_ = offset;
   }
   void set_top_controls_delta(float delta) {
     top_controls_delta_ = delta;
   }
   void set_sent_top_controls_delta(float sent_delta) {
     sent_top_controls_delta_ = sent_delta;
   }
 
   float top_controls_layout_height() const {
     return top_controls_layout_height_;
   }
-  float top_controls_top_offset() const {
-    return top_controls_top_offset_;
+  float top_controls_content_offset() const {
+    return top_controls_content_offset_;
   }
   float top_controls_delta() const {
     return top_controls_delta_;
   }
   float sent_top_controls_delta() const {
     return sent_top_controls_delta_;
   }
-  float total_top_controls_top_offset() const {
-    return top_controls_top_offset_ + top_controls_delta_;
+  float total_top_controls_content_offset() const {
+    return top_controls_content_offset_ + top_controls_delta_;
   }
 
  protected:
   explicit LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl);
   void ReleaseResourcesRecursive(LayerImpl* current);
 
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
@@ skipping 49 matching lines @@
 
   int render_surface_layer_list_id_;
 
   // The top controls content offset at the time of the last layout (and thus,
   // viewport resize) in Blink. i.e. How much the viewport was shrunk by the top
   // controls.
   float top_controls_layout_height_;
 
   // The up-to-date content offset of the top controls, i.e. the amount that the
   // web contents have been shifted down from the top of the device viewport.
-  float top_controls_top_offset_;
+  float top_controls_content_offset_;
   float top_controls_delta_;
   float sent_top_controls_delta_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_