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

chrome/browser/chromeos/status/status_area_button.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 CHROME_BROWSER_CHROMEOS_STATUS_STATUS_AREA_BUTTON_H_
 #define CHROME_BROWSER_CHROMEOS_STATUS_STATUS_AREA_BUTTON_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/string16.h"
@@ skipping 36 matching lines @@
     // Handle visibility changes (e.g. resize the status area).
     virtual void ButtonVisibilityChanged(views::View* button_view) = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
   StatusAreaButton(Delegate* button_delegate,
                    views::ViewMenuDelegate* menu_delegate);
   virtual ~StatusAreaButton() {}
-  virtual void PaintButton(gfx::Canvas* canvas, PaintButtonMode mode) OVERRIDE;
+  virtual void PaintButton(gfx::CanvasSkia* canvas,
+                           PaintButtonMode mode) OVERRIDE;
 
   // Overrides TextButton's SetText to clear max text size before seting new
   // text content so that the button size would fit the new text size.
   virtual void SetText(const string16& text) OVERRIDE;
 
   // views::MenuButton overrides.
   virtual bool Activate() OVERRIDE;
 
   // View overrides.
   virtual gfx::Size GetPreferredSize() OVERRIDE;
@@ skipping 35 matching lines @@
   Delegate* delegate_;
 
   // Fonts used to render the button's text.
   gfx::Font light_font_;
   gfx::Font bold_font_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaButton);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_STATUS_STATUS_AREA_BUTTON_H_