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

ash/wm/dialog_frame_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 ASH_WM_DIALOG_FRAME_VIEW_H_
 #define ASH_WM_DIALOG_FRAME_VIEW_H_
 #pragma once
 
 #include "ui/views/controls/button/button.h"
 #include "ui/views/window/non_client_view.h"
@@ skipping 27 matching lines @@
       const gfx::Rect& client_bounds) const OVERRIDE;
   virtual int NonClientHitTest(const gfx::Point& point) OVERRIDE;
   virtual void GetWindowMask(const gfx::Size& size,
                              gfx::Path* window_mask) OVERRIDE;
   virtual void ResetWindowControls() OVERRIDE;
   virtual void UpdateWindowIcon() OVERRIDE;
 
   // Overridden from View:
   virtual std::string GetClassName() const OVERRIDE;
   virtual void Layout() OVERRIDE;
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
 
   // Overridden from views::ButtonListener:
   virtual void ButtonPressed(views::Button* sender,
                              const views::Event& event) OVERRIDE;
 
  private:
   gfx::Insets GetPaddingInsets() const;
   gfx::Insets GetClientInsets() const;
 
   gfx::Rect title_display_rect_;
 
   views::ImageButton* close_button_;
 
   static gfx::Font* title_font_;
 
   DISALLOW_COPY_AND_ASSIGN(DialogFrameView);
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // ASH_WM_DIALOG_FRAME_VIEW_H_