Reduce forward declarations in core/svg

Source/core/svg/SVGDocumentExtensions.h

 /*
  * Copyright (C) 2006 Apple Inc. All rights reserved.
  * Copyright (C) 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * 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 20 matching lines @@
 namespace WebCore {
 
 class Document;
 class RenderSVGResourceContainer;
 class SubtreeLayoutScope;
 class SVGElement;
 #if ENABLE(SVG_FONTS)
 class SVGFontFaceElement;
 #endif
 class SVGResourcesCache;
-class SVGSMILElement;
 class SVGSVGElement;
 class Element;
 
 typedef WillBeHeapHashSet<RawPtrWillBeMember<SVGElement> > SVGElementSet;
 
 class SVGDocumentExtensions : public NoBaseWillBeGarbageCollectedFinalized<SVGDocumentExtensions> {
     WTF_MAKE_NONCOPYABLE(SVGDocumentExtensions); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     typedef HashSet<Element*> SVGPendingElements;
     explicit SVGDocumentExtensions(Document*);
@@ skipping 85 matching lines @@
     void markPendingResourcesForRemoval(const AtomicString&);
     Element* removeElementFromPendingResourcesForRemoval(const AtomicString&);
 
 private:
     PassOwnPtr<SVGPendingElements> removePendingResourceForRemoval(const AtomicString&);
 };
 
 }
 
 #endif