Make sure the rootNode of a LiveNodeListBase is always a ContainerNode

Source/core/html/HTMLOptionsCollection.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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.
@@ skipping 16 matching lines @@
 #include "core/html/HTMLCollection.h"
 
 namespace WebCore {
 
 class ExceptionState;
 class HTMLOptionElement;
 class HTMLSelectElement;
 
 class HTMLOptionsCollection FINAL : public HTMLCollection {
 public:
-    static PassRefPtr<HTMLOptionsCollection> create(Node*, CollectionType);
+    static PassRefPtr<HTMLOptionsCollection> create(ContainerNode*, CollectionType);
 
     void add(PassRefPtr<HTMLOptionElement>, ExceptionState&);
     void add(PassRefPtr<HTMLOptionElement>, int index, ExceptionState&);
     void remove(int index);
     void remove(HTMLOptionElement*);
 
     int selectedIndex() const;
     void setSelectedIndex(int);
 
     void setLength(unsigned, ExceptionState&);
     void anonymousNamedGetter(const AtomicString& name, bool&, RefPtr<NodeList>&, bool&, RefPtr<Node>&);
     bool anonymousIndexedSetter(unsigned, PassRefPtr<HTMLOptionElement>, ExceptionState&);
     bool anonymousIndexedSetterRemove(unsigned, ExceptionState&);
 
 private:
-    explicit HTMLOptionsCollection(Node*);
+    explicit HTMLOptionsCollection(ContainerNode*);
 };
 
 } //namespace
 
 #endif