Clean up forward declarations in Source/platform

Source/platform/graphics/filters/Filter.h

 /*
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 11 matching lines @@
 #define Filter_h
 
 #include "platform/PlatformExport.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "wtf/RefCounted.h"
 
 namespace blink {
 
-class FilterEffect;
-
 class PLATFORM_EXPORT Filter : public RefCounted<Filter> {
 public:
     Filter(const AffineTransform& absoluteTransform)
     : m_absoluteTransform(absoluteTransform)
     , m_inverseTransform(absoluteTransform.inverse())
     {
         // Filters can only accept scaling and translating transformations, as coordinates
         // in most primitives are given in horizontal and vertical directions.
         ASSERT(!absoluteTransform.b() && !absoluteTransform.c());
     }
@@ skipping 42 matching lines @@
     OwnPtr<ImageBuffer> m_sourceImage;
     AffineTransform m_absoluteTransform;
     AffineTransform m_inverseTransform;
     FloatRect m_absoluteFilterRegion;
     FloatRect m_filterRegion;
 };
 
 } // namespace blink
 
 #endif // Filter_h