Have Frame::script() return a reference

Source/core/html/HTMLDocument.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 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 202 matching lines @@
 // --------------------------------------------------------------------------
 // not part of the DOM
 // --------------------------------------------------------------------------
 
 void HTMLDocument::addItemToMap(HashCountedSet<AtomicString>& map, const AtomicString& name)
 {
     if (name.isEmpty())
         return;
     map.add(name);
     if (Frame* f = frame())
-        f->script()->namedItemAdded(this, name);
+        f->script().namedItemAdded(this, name);
 }
 
 void HTMLDocument::removeItemFromMap(HashCountedSet<AtomicString>& map, const AtomicString& name)
 {
     if (name.isEmpty())
         return;
     map.remove(name);
     if (Frame* f = frame())
-        f->script()->namedItemRemoved(this, name);
+        f->script().namedItemRemoved(this, name);
 }
 
 void HTMLDocument::addNamedItem(const AtomicString& name)
 {
     addItemToMap(m_namedItemCounts, name);
 }
 
 void HTMLDocument::removeNamedItem(const AtomicString& name)
 {
     removeItemFromMap(m_namedItemCounts, name);
@@ skipping 77 matching lines @@
 }
 
 void HTMLDocument::clear()
 {
     // FIXME: This does nothing, and that seems unlikely to be correct.
     // We've long had a comment saying that IE doesn't support this.
     // But I do see it in the documentation for Mozilla.
 }
 
 }