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

ui/views/controls/throbber.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_THROBBER_H_
 #define UI_VIEWS_CONTROLS_THROBBER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/time.h"
@@ skipping 18 matching lines @@
 
   // Start and stop the throbber animation
   virtual void Start();
   virtual void Stop();
 
   // Set custom throbber frames. Otherwise IDR_THROBBER is loaded.
   void SetFrames(SkBitmap* frames);
 
   // overridden from View
   virtual gfx::Size GetPreferredSize() OVERRIDE;
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
 
  protected:
   // Specifies whether the throbber is currently animating or not
   bool running_;
 
  private:
   void Run();
 
   bool paint_while_stopped_;
   int frame_count_;  // How many frames we have.
@@ skipping 49 matching lines @@
 //
 class VIEWS_EXPORT CheckmarkThrobber : public Throbber {
  public:
   CheckmarkThrobber();
 
   // If checked is true, the throbber stops spinning and displays a checkmark.
   // If checked is false, the throbber stops spinning and displays nothing.
   void SetChecked(bool checked);
 
   // Overridden from Throbber:
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnPaint(gfx::CanvasSkia* canvas) OVERRIDE;
 
  private:
   static const int kFrameTimeMs = 30;
 
   static void InitClass();
 
   // Whether or not we should display a checkmark.
   bool checked_;
 
   // The checkmark image.
   static SkBitmap* checkmark_;
 
   DISALLOW_COPY_AND_ASSIGN(CheckmarkThrobber);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_THROBBER_H_