Make sure the rootNode of a LiveNodeListBase is always a ContainerNode

Source/core/html/RadioNodeList.cpp

 /*
  * Copyright (c) 2012 Motorola Mobility, Inc. All rights reserved.
  *
  * 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 19 matching lines @@
 #include "core/dom/Element.h"
 #include "core/dom/NodeRareData.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLObjectElement.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
-RadioNodeList::RadioNodeList(Node* rootNode, const AtomicString& name, CollectionType type)
+RadioNodeList::RadioNodeList(ContainerNode* rootNode, const AtomicString& name, CollectionType type)
     : LiveNodeList(rootNode, type, InvalidateForFormControls, rootNode->hasTagName(formTag) ? NodeListIsRootedAtDocument : NodeListIsRootedAtNode)
     , m_name(name)
     , m_onlyMatchImgElements(type == RadioImgNodeListType)
 {
     ScriptWrappable::init(this);
 }
 
 RadioNodeList::~RadioNodeList()
 {
     ownerNode()->nodeLists()->removeCacheWithAtomicName(this, m_onlyMatchImgElements ? RadioImgNodeListType : RadioNodeListType, m_name);
@@ skipping 60 matching lines @@
         return false;
 
     if (testElement.hasTagName(inputTag) && toHTMLInputElement(testElement).isImageButton())
         return false;
 
     return checkElementMatchesRadioNodeListFilter(testElement);
 }
 
 } // namespace