[Mac] Rubber-banding on Lion.

content/renderer/render_widget.h

 // Copyright (c) 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 CONTENT_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 232 matching lines @@
   virtual webkit::ppapi::PluginInstance* GetBitmapForOptimizedPluginPaint(
       const gfx::Rect& paint_bounds,
       TransportDIB** dib,
       gfx::Rect* location,
       gfx::Rect* clip);
 
   // Gets the scroll offset of this widget, if this widget has a notion of
   // scroll offset.
   virtual gfx::Point GetScrollOffset();
 
+  // Gets the dimensions of the content area.
+  virtual gfx::Size GetContentsSize();
+
   // Sets the "hidden" state of this widget.  All accesses to is_hidden_ should
   // use this method so that we can properly inform the RenderThread of our
   // state.
   void SetHidden(bool hidden);
 
   bool is_hidden() const { return is_hidden_; }
 
   // True if an UpdateRect_ACK message is pending.
   bool update_reply_pending() const {
     return update_reply_pending_;
@@ skipping 171 matching lines @@
   bool animation_task_posted_;
   bool invalidation_task_posted_;
 
   bool has_disable_gpu_vsync_switch_;
   base::TimeTicks last_do_deferred_update_time_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_