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

ui/views/controls/focusable_border.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_FOCUSABLE_BORDER_H_
 #define UI_VIEWS_CONTROLS_FOCUSABLE_BORDER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/views/border.h"
 #include "ui/views/view.h"
 
 namespace gfx {
-class Canvas;
+class CanvasSkia;
 class Insets;
 }
 
 namespace views {
 
 // A Border class to draw a focused border around a field (e.g textfield).
 class FocusableBorder : public Border {
  public:
   FocusableBorder();
 
   // Sets the insets of the border.
   void SetInsets(int top, int left, int bottom, int right);
 
   // Sets the focus state.
   void set_has_focus(bool has_focus) {
     has_focus_ = has_focus;
   }
 
   // Overridden from Border:
-  virtual void Paint(const View& view, gfx::Canvas* canvas) const OVERRIDE;
+  virtual void Paint(const View& view, gfx::CanvasSkia* canvas) const OVERRIDE;
   virtual void GetInsets(gfx::Insets* insets) const OVERRIDE;
 
  private:
   bool has_focus_;
   gfx::Insets insets_;
 
   DISALLOW_COPY_AND_ASSIGN(FocusableBorder);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_FOCUSABLE_BORDER_H_