Have Element::ensureUniqueElementData() return a reference

Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 256 matching lines @@
 void HTMLSelectElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == sizeAttr) {
         int oldSize = m_size;
         // Set the attribute value to a number.
         // This is important since the style rules for this attribute can determine the appearance property.
         int size = value.toInt();
         AtomicString attrSize = AtomicString::number(size);
         if (attrSize != value) {
             // FIXME: This is horribly factored.
-            if (Attribute* sizeAttribute = ensureUniqueElementData()->getAttributeItem(sizeAttr))
+            if (Attribute* sizeAttribute = ensureUniqueElementData().getAttributeItem(sizeAttr))
                 sizeAttribute->setValue(attrSize);
         }
         size = max(size, 1);
 
         // Ensure that we've determined selectedness of the items at least once prior to changing the size.
         if (oldSize != size)
             updateListItemSelectedStates();
 
         m_size = size;
         setNeedsValidityCheck();
@@ skipping 1273 matching lines @@
 {
     return true;
 }
 
 bool HTMLSelectElement::supportsAutofocus() const
 {
     return true;
 }
 
 } // namespace