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

ui/gfx/canvas_skia.cc

 // 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.
 
 #include "ui/gfx/canvas_skia.h"
 
 #include <limits>
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
@@ skipping 345 matching lines @@
 }
 
 void CanvasSkia::EndPlatformPaint() {
   skia::EndPlatformPaint(canvas_);
 }
 
 void CanvasSkia::Transform(const ui::Transform& transform) {
   canvas_->concat(transform.matrix());
 }
 
-CanvasSkia* CanvasSkia::AsCanvasSkia() {
-  return this;
-}
-
-const CanvasSkia* CanvasSkia::AsCanvasSkia() const {
-  return this;
-}
-
 SkCanvas* CanvasSkia::GetSkCanvas() {
   return canvas_;
 }
 
 const SkCanvas* CanvasSkia::GetSkCanvas() const {
   return canvas_;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // CanvasSkia, private:
 
 bool CanvasSkia::IntersectsClipRectInt(int x, int y, int w, int h) {
   SkRect clip;
   return canvas_->getClipBounds(&clip) &&
       clip.intersect(SkIntToScalar(x), SkIntToScalar(y), SkIntToScalar(x + w),
                      SkIntToScalar(y + h));
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// Canvas, public:
-
-Canvas* Canvas::CreateCanvas() {
-  return new CanvasSkia;
-}
-
-Canvas* Canvas::CreateCanvas(const gfx::Size& size, bool is_opaque) {
-  return new CanvasSkia(size, is_opaque);
-}
-
 }  // namespace gfx