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

chrome/browser/chromeos/panels/panel_scroller_header.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 CHROME_BROWSER_CHROMEOS_PANELS_PANEL_SCROLLER_HEADER_H_
 #define CHROME_BROWSER_CHROMEOS_PANELS_PANEL_SCROLLER_HEADER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/string16.h"
 #include "ui/views/view.h"
 
 class PanelScroller;
 
 class PanelScrollerHeader : public views::View {
  public:
   explicit PanelScrollerHeader(PanelScroller* scroller);
   virtual ~PanelScrollerHeader();
 
   void set_title(const string16& title) { title_ = title; }
 
   // views::View overrides.
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual bool OnMouseDragged(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseCaptureLost() OVERRIDE;
   virtual gfx::Size GetPreferredSize() OVERRIDE;
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
 
  private:
   // Non-owning pointer to our parent scroller object.
   PanelScroller* scroller_;
 
   string16 title_;
 
   DISALLOW_COPY_AND_ASSIGN(PanelScrollerHeader);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_PANELS_PANEL_SCROLLER_HEADER_H_