Add Vector2d classes that represent offsets, instead of using Point.

content/renderer/render_widget.h

 // Copyright (c) 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 CONTENT_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 310 matching lines @@
   // should continue with the normal painting code path.
   virtual webkit::ppapi::PluginInstance* GetBitmapForOptimizedPluginPaint(
       const gfx::Rect& paint_bounds,
       TransportDIB** dib,
       gfx::Rect* location,
       gfx::Rect* clip,
       float* scale_factor);
 
   // Gets the scroll offset of this widget, if this widget has a notion of
   // scroll offset.
-  virtual gfx::Point GetScrollOffset();
+  virtual gfx::Vector2d GetScrollOffset();
 
   // 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);
 
   void WillToggleFullscreen();
   void DidToggleFullscreen();
 
   bool next_paint_is_resize_ack() const;
@@ skipping 263 matching lines @@
   typedef std::map<int, SmoothScrollCompletionCallback>
       PendingSmoothScrollGestureMap;
   PendingSmoothScrollGestureMap pending_smooth_scroll_gestures_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_