Reduce forward declarations in core/rendering

Source/core/rendering/svg/SVGRootInlineBox.h

 /*
  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
  * Copyright (C) 2006 Apple Computer Inc.
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) Research In Motion Limited 2010. 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.
@@ skipping 11 matching lines @@
 
 #ifndef SVGRootInlineBox_h
 #define SVGRootInlineBox_h
 
 #include "core/rendering/RootInlineBox.h"
 #include "core/rendering/svg/SVGRenderSupport.h"
 #include "core/rendering/svg/SVGTextLayoutEngine.h"
 
 namespace WebCore {
 
-class SVGInlineTextBox;
-
 class SVGRootInlineBox FINAL : public RootInlineBox {
 public:
     SVGRootInlineBox(RenderBlockFlow& block)
         : RootInlineBox(block)
         , m_logicalHeight(0)
     {
     }
 
     virtual bool isSVGRootInlineBox() const OVERRIDE { return true; }
 
@@ skipping 16 matching lines @@
 
 private:
     float m_logicalHeight;
 };
 
 DEFINE_INLINE_BOX_TYPE_CASTS(SVGRootInlineBox);
 
 } // namespace WebCore
 
 #endif // SVGRootInlineBox_h