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

content/renderer/pepper/pepper_platform_image_2d_impl.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_PEPPER_PEPPER_PLATFORM_IMAGE_2D_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_IMAGE_2D_IMPL_H_
 
 #include "base/basictypes.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 
 namespace content {
 
 // Implements the Image2D using a TransportDIB.
 class PepperPlatformImage2DImpl
     : public webkit::ppapi::PluginDelegate::PlatformImage2D {
  public:
   virtual ~PepperPlatformImage2DImpl();
 
   // Factory function that properly allocates a TransportDIB according to
   // the platform. Returns NULL on failure.
   static PepperPlatformImage2DImpl* Create(int width, int height);
 
   // PlatformImage2D implementation.
-  virtual skia::PlatformCanvas* Map() OVERRIDE;
+  virtual SkCanvas* Map() OVERRIDE;
   virtual intptr_t GetSharedMemoryHandle(uint32* byte_count) const OVERRIDE;
   virtual TransportDIB* GetTransportDIB() const OVERRIDE;
 
  private:
   // This constructor will take ownership of the dib pointer.
   // On Mac, we assume that the dib is cached by the browser, so on destruction
   // we'll tell the browser to free it.
   PepperPlatformImage2DImpl(int width, int height, TransportDIB* dib);
 
   int width_;
   int height_;
   scoped_ptr<TransportDIB> dib_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperPlatformImage2DImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_IMAGE_2D_IMPL_H_