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

ui/gfx/canvas_skia_paint.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 UI_GFX_CANVAS_SKIA_PAINT_H_
 #define UI_GFX_CANVAS_SKIA_PAINT_H_
 #pragma once
 
 #include "base/logging.h"
 #include "skia/ext/canvas_paint.h"
-#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/canvas.h"
 
 // Define a gfx::CanvasSkiaPaint type that wraps our gfx::Canvas like the
 // skia::PlatformCanvasPaint wraps PlatformCanvas.
 
 namespace skia {
 
 template<> inline
-PlatformCanvas* GetPlatformCanvas(skia::CanvasPaintT<gfx::CanvasSkia>* canvas) {
+PlatformCanvas* GetPlatformCanvas(skia::CanvasPaintT<gfx::Canvas>* canvas) {
   PlatformCanvas* platform_canvas = canvas->platform_canvas();
   DCHECK(platform_canvas);
   return platform_canvas;
 }
 
 }  // namespace skia
 
 namespace gfx {
 
-typedef skia::CanvasPaintT<CanvasSkia> CanvasSkiaPaint;
+typedef skia::CanvasPaintT<Canvas> CanvasSkiaPaint;
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CANVAS_SKIA_PAINT_H_