Reduce forward declarations in core/rendering

Source/core/rendering/FilterEffectRenderer.h

 /*
  * Copyright (C) 2011 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 #include "platform/graphics/filters/Filter.h"
 #include "platform/graphics/filters/FilterEffect.h"
 #include "platform/graphics/filters/FilterOperations.h"
 #include "platform/graphics/filters/SourceGraphic.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
-class Document;
 class GraphicsContext;
 class RenderLayer;
 class RenderObject;
 
 class FilterEffectRendererHelper {
 public:
     FilterEffectRendererHelper(bool haveFilterEffect)
         : m_savedGraphicsContext(0)
         , m_renderLayer(0)
         , m_haveFilterEffect(haveFilterEffect)
@@ skipping 63 matching lines @@
     IntRectExtent m_outsets;
 
     bool m_graphicsBufferAttached;
     bool m_hasFilterThatMovesPixels;
 };
 
 } // namespace WebCore
 
 
 #endif // FilterEffectRenderer_h