Make sure the rootNode of a LiveNodeListBase is always a ContainerNode

Source/core/dom/ClassNodeList.cpp

 /*
  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2007 David Smith (catfish.man@gmail.com)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 17 matching lines @@
  */
 
 #include "config.h"
 #include "core/dom/ClassNodeList.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/NodeRareData.h"
 
 namespace WebCore {
 
-ClassNodeList::ClassNodeList(PassRefPtr<Node> rootNode, const AtomicString& classNames)
+ClassNodeList::ClassNodeList(PassRefPtr<ContainerNode> rootNode, const AtomicString& classNames)
     : LiveNodeList(rootNode, ClassNodeListType, InvalidateOnClassAttrChange)
     , m_classNames(classNames, document().inQuirksMode())
     , m_originalClassNames(classNames)
 {
 }
 
 ClassNodeList::~ClassNodeList()
 {
     ownerNode()->nodeLists()->removeCacheWithAtomicName(this, ClassNodeListType, m_originalClassNames);
 }
 
 bool ClassNodeList::nodeMatches(const Element& testNode) const
 {
     return nodeMatchesInlined(testNode);
 }
 
 } // namespace WebCore