Reduce number of header includes in SVG

Source/core/svg/SVGElementInstanceList.cpp

 /*
  * Copyright (C) 2007 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.
  */
 
 #include "config.h"
 
 #include "core/svg/SVGElementInstanceList.h"
+#include "core/svg/SVGElementInstance.h"
 
 namespace WebCore {
 
 SVGElementInstanceList::SVGElementInstanceList(PassRefPtr<SVGElementInstance> rootInstance)
     : m_rootInstance(rootInstance)
 {
     ScriptWrappable::init(this);
 }
 
 SVGElementInstanceList::~SVGElementInstanceList()
@@ skipping 14 matching lines @@
     unsigned pos = 0;
     SVGElementInstance* instance = m_rootInstance->firstChild();
     while (instance && pos < index) {
         instance = instance->nextSibling();
         pos++;
     }
     return instance;
 }
 
 }