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

content/renderer/pepper/pepper_platform_image_2d_impl.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 "content/renderer/pepper/pepper_platform_image_2d_impl.h"
 
 #include "build/build_config.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 #include "ui/surface/transport_dib.h"
@@ skipping 45 matching lines @@
 #else
   static int next_dib_id = 0;
   TransportDIB* dib = TransportDIB::Create(buffer_size, next_dib_id++);
   if (!dib)
     return NULL;
 #endif
 
   return new PepperPlatformImage2DImpl(width, height, dib);
 }
 
-skia::PlatformCanvas* PepperPlatformImage2DImpl::Map() {
+SkCanvas* PepperPlatformImage2DImpl::Map() {
   return dib_->GetPlatformCanvas(width_, height_);
 }
 
 intptr_t PepperPlatformImage2DImpl::GetSharedMemoryHandle(
     uint32* byte_count) const {
   *byte_count = dib_->size();
 #if defined(OS_WIN)
   return reinterpret_cast<intptr_t>(dib_->handle());
 #elif defined(OS_MACOSX) || defined(OS_ANDROID)
   return static_cast<intptr_t>(dib_->handle().fd);
 #elif defined(OS_POSIX)
   return static_cast<intptr_t>(dib_->handle());
 #endif
 }
 
 TransportDIB* PepperPlatformImage2DImpl::GetTransportDIB() const {
   return dib_.get();
 }
 
 }  // namespace content