Have HTMLFormElement's named getter return a RadioNodeList.

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 89 matching lines @@
 {
     if (!testElement->hasTagName(objectTag) && !testElement->isFormControlElement())
         return false;
 
     if (testElement->hasTagName(inputTag) && toHTMLInputElement(testElement)->isImageButton())
         return false;
 
     return checkElementMatchesRadioNodeListFilter(testElement);
 }
 
+RadioImgNodeList::RadioImgNodeList(Node* rootNode, const AtomicString& name) : RadioNodeList(rootNode, name) { }
+
+bool RadioImgNodeList::nodeMatches(Element* testElement) const
+{
+    return testElement->hasTagName(imgTag);
+}
+
 } // namspace