ui/gfx: Make gfx::Canvas inherit from gfx::CanvasSkia.

ui/views/widget/root_view.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 UI_VIEWS_WIDGET_ROOT_VIEW_H_
 #define UI_VIEWS_WIDGET_ROOT_VIEW_H_
 #pragma once
 
 #include <string>
 
@@ skipping 97 matching lines @@
   virtual ui::TouchStatus OnTouchEvent(const TouchEvent& event) OVERRIDE;
   virtual ui::GestureStatus OnGestureEvent(const GestureEvent& event) OVERRIDE;
   virtual void SetMouseHandler(View* new_mouse_handler) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
   virtual void ReorderChildLayers(ui::Layer* parent_layer) OVERRIDE;
 
  protected:
   // Overridden from View:
   virtual void ViewHierarchyChanged(bool is_add, View* parent,
                                     View* child) OVERRIDE;
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
   virtual void CalculateOffsetToAncestorWithLayer(
       gfx::Point* offset,
       ui::Layer** layer_parent) OVERRIDE;
 
  private:
   friend class View;
   friend class Widget;
 
   // Input ---------------------------------------------------------------------
 
@@ skipping 63 matching lines @@
   // Tracks drag state for a view.
   View::DragInfo drag_info_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(RootView);
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_ROOT_VIEW_H_