Remove duplicated headers from core/

Source/core/platform/graphics/Canvas2DLayerBridge.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 13 matching lines @@
  */
 
 #include "config.h"
 
 #include "core/platform/graphics/Canvas2DLayerBridge.h"
 
 #include "GrContext.h"
 #include "SkDevice.h"
 #include "SkSurface.h"
 #include "core/platform/graphics/Canvas2DLayerManager.h"
-#include "core/platform/graphics/GraphicsContext3D.h"
 #include "core/platform/graphics/GraphicsLayer.h"
 #include "core/platform/graphics/gpu/SharedGraphicsContext3D.h"
 #include "platform/TraceEvent.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCompositorSupport.h"
 #include "public/platform/WebGraphicsContext3D.h"
 
 using blink::WebExternalTextureLayer;
 using blink::WebGraphicsContext3D;
 
@@ skipping 372 matching lines @@
 Canvas2DLayerBridge::MailboxInfo::MailboxInfo(const MailboxInfo& other) {
     // This copy constructor should only be used for Vector reallocation
     // Assuming 'other' is to be destroyed, we swap m_image ownership
     // rather than do a refcount dance.
     memcpy(&m_mailbox, &other.m_mailbox, sizeof(m_mailbox));
     m_image.swap(const_cast<SkAutoTUnref<SkImage>*>(&other.m_image));
     m_status = other.m_status;
 }
 
 }