Reduce number of header includes in 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGDocumentExtensions_h
 #define SVGDocumentExtensions_h
 
 #include <wtf/Forward.h>
 #include <wtf/HashMap.h>
 #include <wtf/HashSet.h>
-#include <wtf/PassOwnPtr.h>
 #include <wtf/text/AtomicStringHash.h>
-#include <wtf/text/StringImpl.h>
 
 namespace WebCore {
 
 class Document;
 class RenderSVGResourceContainer;
 class SVGElement;
 #if ENABLE(SVG_FONTS)
 class SVGFontFaceElement;
 #endif
 class SVGResourcesCache;
@@ skipping 65 matching lines @@
     void markPendingResourcesForRemoval(const AtomicString&);
     Element* removeElementFromPendingResourcesForRemoval(const AtomicString&);
 
 private:
     PassOwnPtr<SVGPendingElements> removePendingResourceForRemoval(const AtomicString&);
 };
 
 }
 
 #endif