Use stricter typing for HTMLCollection named getter

Source/web/WebFormElement.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 61 matching lines @@
 }
 
 void WebFormElement::submit()
 {
     unwrap<HTMLFormElement>()->submit();
 }
 
 void WebFormElement::getNamedElements(const WebString& name,
                                       WebVector<WebNode>& result)
 {
-    Vector<RefPtr<Node> > tempVector;
+    Vector<RefPtr<Element> > tempVector;
     unwrap<HTMLFormElement>()->getNamedElements(name, tempVector);
     result.assign(tempVector);
 }
 
 void WebFormElement::getFormControlElements(WebVector<WebFormControlElement>& result) const
 {
     const HTMLFormElement* form = constUnwrap<HTMLFormElement>();
     Vector<RefPtr<HTMLFormControlElement> > formControlElements;
 
     const Vector<FormAssociatedElement*>& associatedElements = form->associatedElements();
@@ skipping 24 matching lines @@
     m_private = e;
     return *this;
 }
 
 WebFormElement::operator PassRefPtr<HTMLFormElement>() const
 {
     return toHTMLFormElement(m_private.get());
 }
 
 } // namespace blink