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

ui/aura/window.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/aura/window.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 690 matching lines @@
 
 void Window::NotifyAddedToRootWindow() {
   FOR_EACH_OBSERVER(WindowObserver, observers_,
                     OnWindowAddedToRootWindow(this));
   for (Window::Windows::const_iterator it = children_.begin();
        it != children_.end(); ++it) {
     (*it)->NotifyAddedToRootWindow();
   }
 }
 
-void Window::OnPaintLayer(gfx::Canvas* canvas) {
+void Window::OnPaintLayer(gfx::CanvasSkia* canvas) {
   if (delegate_)
     delegate_->OnPaint(canvas);
 }
 
 void Window::UpdateLayerName(const std::string& name) {
 #if !defined(NDEBUG)
   DCHECK(layer());
 
   std::string layer_name(name_);
   if (layer_name.empty())
@@ skipping 13 matching lines @@
                                         parent_->children().end(),
                                         this);
   for (++i; i != parent_->children().end(); ++i) {
     if ((*i)->StopsEventPropagation())
       return true;
   }
   return false;
 }
 
 }  // namespace aura