Simplify platform_canvas.h by recognizing that PlatformCanvas does not actually extend

content/renderer/render_widget.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 CONTENT_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 29 matching lines @@
 namespace IPC {
 class SyncMessage;
 }
 
 namespace WebKit {
 class WebGestureEvent;
 class WebMouseEvent;
 class WebTouchEvent;
 }
 
-namespace skia {
-class PlatformCanvas;
-}
-
 namespace ui {
 class Range;
 }
 
 namespace webkit {
 namespace npapi {
 struct WebPluginGeometry;
 }  // namespace npapi
 
 namespace ppapi {
@@ skipping 156 matching lines @@
   // Sets whether this RenderWidget has been swapped out to be displayed by
   // a RenderWidget in a different process.  If so, no new IPC messages will be
   // sent (only ACKs) and the process is free to exit when there are no other
   // active RenderWidgets.
   void SetSwappedOut(bool is_swapped_out);
 
   // Paints the given rectangular region of the WebWidget into canvas (a
   // shared memory segment returned by AllocPaintBuf on Windows). The caller
   // must ensure that the given rect fits within the bounds of the WebWidget.
   void PaintRect(const gfx::Rect& rect, const gfx::Point& canvas_origin,
-                 skia::PlatformCanvas* canvas);
+                 SkCanvas* canvas);
 
   // Paints a border at the given rect for debugging purposes.
-  void PaintDebugBorder(const gfx::Rect& rect, skia::PlatformCanvas* canvas);
+  void PaintDebugBorder(const gfx::Rect& rect, SkCanvas* canvas);
 
   bool IsRenderingVSynced();
   void AnimationCallback();
   void AnimateIfNeeded();
   void InvalidationCallback();
   void DoDeferredUpdateAndSendInputAck();
   void DoDeferredUpdate();
   void DoDeferredClose();
   void DoDeferredSetWindowRect(const WebKit::WebRect& pos);
 
@@ skipping 379 matching lines @@
 
   // Specified whether the compositor will run in its own thread.
   bool is_threaded_compositing_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_