Have LiveNodeListBase::ownerNode() return a reference

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 29 matching lines @@
 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()->removeCache(this, m_onlyMatchImgElements ? RadioImgNodeListType : RadioNodeListType, m_name);
+    ownerNode().nodeLists()->removeCache(this, m_onlyMatchImgElements ? RadioImgNodeListType : RadioNodeListType, m_name);
 }
 
 static inline HTMLInputElement* toRadioButtonInputElement(Node* node)
 {
     ASSERT(node->isElementNode());
     if (!node->hasTagName(inputTag))
         return 0;
     HTMLInputElement* inputElement = toHTMLInputElement(node);
     if (!inputElement->isRadioButton() || inputElement->value().isEmpty())
         return 0;
@@ skipping 25 matching lines @@
             continue;
         inputElement->setChecked(true);
         return;
     }
 }
 
 bool RadioNodeList::checkElementMatchesRadioNodeListFilter(const Element& testElement) const
 {
     ASSERT(!m_onlyMatchImgElements);
     ASSERT(testElement.hasTagName(objectTag) || testElement.isFormControlElement());
-    if (ownerNode()->hasTagName(formTag)) {
+    if (ownerNode().hasTagName(formTag)) {
         HTMLFormElement* formElement = toHTMLElement(testElement).formOwner();
         if (!formElement || formElement != ownerNode())
             return false;
     }
 
     return testElement.getIdAttribute() == m_name || testElement.getNameAttribute() == m_name;
 }
 
 bool RadioNodeList::nodeMatches(const Element& testElement) const
 {
     if (m_onlyMatchImgElements)
         return testElement.hasTagName(imgTag);
 
     if (!testElement.hasTagName(objectTag) && !testElement.isFormControlElement())
         return false;
 
     if (testElement.hasTagName(inputTag) && toHTMLInputElement(testElement).isImageButton())
         return false;
 
     return checkElementMatchesRadioNodeListFilter(testElement);
 }
 
 } // namespace