Support bottom-right anchored fixed-position elements during a pinch gesture

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 <string>
 #include <vector>
 
@@ skipping 193 matching lines @@
   void UpdateSolidColorScrollbars();
 
   // Hide existence of pinch-zoom scrollbars.
   void UpdatePinchZoomScrollbars();
   void FadeInPinchZoomScrollbars();
   void FadeOutPinchZoomScrollbars();
   ScrollbarLayerImpl* PinchZoomScrollbarHorizontal();
   ScrollbarLayerImpl* PinchZoomScrollbarVertical();
   bool HasPinchZoomScrollbars() const;
 
+  void UpdateRootScrollLayerSizeDelta();
+
   LayerTreeHostImpl* layer_tree_host_impl_;
   int source_frame_number_;
   scoped_ptr<LayerImpl> root_layer_;
   HeadsUpDisplayLayerImpl* hud_layer_;
   LayerImpl* root_scroll_layer_;
   LayerImpl* currently_scrolling_layer_;
   SkColor background_color_;
   bool has_transparent_background_;
 
   int pinch_zoom_scrollbar_horizontal_layer_id_;
@@ skipping 22 matching lines @@
   // In impl-side painting mode, this is true when the tree may contain
   // structural differences relative to the active tree.
   bool needs_full_tree_sync_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_IMPL_H_