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

ui/views/controls/button/checkbox.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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_CONTROLS_BUTTON_CHECKBOX_H_
 #define UI_VIEWS_CONTROLS_BUTTON_CHECKBOX_H_
 #pragma once
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 17 matching lines @@
 
   // Sets/Gets whether or not the checkbox is checked.
   virtual void SetChecked(bool checked);
   bool checked() const { return checked_; }
 
  protected:
   // Overridden from View:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual std::string GetClassName() const OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
-  virtual void OnPaintFocusBorder(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaintFocusBorder(gfx::CanvasSkia* canvas) OVERRIDE;
 
  private:
   // Overridden from Button:
   virtual void NotifyClick(const views::Event& event) OVERRIDE;
 
   // Overridden from TextButtonBase:
   virtual gfx::NativeTheme::Part GetThemePart() const OVERRIDE;
   virtual gfx::Rect GetThemePaintRect() const OVERRIDE;
   virtual void GetExtraParams(
       gfx::NativeTheme::ExtraParams* params) const OVERRIDE;
   virtual gfx::Rect GetTextBounds() const OVERRIDE;
 
   // True if the checkbox is checked.
   bool checked_;
 
   DISALLOW_COPY_AND_ASSIGN(Checkbox);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CHECKBOX_H_