Devirtualize several SVG classes destructors

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
@@ skipping 12 matching lines @@
 #include "core/svg/SVGElementInstance.h"
 
 namespace WebCore {
 
 SVGElementInstanceList::SVGElementInstanceList(PassRefPtr<SVGElementInstance> rootInstance)
     : m_rootInstance(rootInstance)
 {
     ScriptWrappable::init(this);
 }
 
-SVGElementInstanceList::~SVGElementInstanceList()
-{
-}
-
 unsigned SVGElementInstanceList::length() const
 {
     // NOTE: We could use the same caching facilities, like the ones "ChildNodeList" uses.
     unsigned length = 0;
     for (SVGElementInstance* instance = m_rootInstance->firstChild(); instance; instance = instance->nextSibling())
         length++;
     return length;
 }
 
 SVGElementInstance* SVGElementInstanceList::item(unsigned index)
 {
     unsigned pos = 0;
     SVGElementInstance* instance = m_rootInstance->firstChild();
     while (instance && pos < index) {
         instance = instance->nextSibling();
         pos++;
     }
     return instance;
 }
 
 }