Add Traversal<*Element>::firstAncestor() API

Source/core/html/HTMLOptionElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Motorola Mobility, Inc.  All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 241 matching lines @@
 {
     if (HTMLDataListElement* dataList = ownerDataListElement())
         dataList->optionElementChildrenChanged();
     else if (HTMLSelectElement* select = ownerSelectElement())
         select->optionElementChildrenChanged();
     HTMLElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 }
 
 HTMLDataListElement* HTMLOptionElement::ownerDataListElement() const
 {
-    for (ContainerNode* parent = parentNode(); parent ; parent = parent->parentNode()) {
-        if (isHTMLDataListElement(*parent))
-            return toHTMLDataListElement(parent);
-    }
-    return 0;
+    return Traversal<HTMLDataListElement>::firstAncestor(*this);
 }
 
 HTMLSelectElement* HTMLOptionElement::ownerSelectElement() const
 {
-    ContainerNode* select = parentNode();
-    while (select && !isHTMLSelectElement(*select))
-        select = select->parentNode();
-
-    if (!select)
-        return 0;
-
-    return toHTMLSelectElement(select);
+    return Traversal<HTMLSelectElement>::firstAncestor(*this);
 }
 
 String HTMLOptionElement::label() const
 {
     const AtomicString& label = fastGetAttribute(labelAttr);
     if (!label.isNull())
         return label;
     return collectOptionInnerText().stripWhiteSpace(isHTMLSpace<UChar>).simplifyWhiteSpace(isHTMLSpace<UChar>);
 }
 
@@ skipping 80 matching lines @@
 
 HTMLFormElement* HTMLOptionElement::form() const
 {
     if (HTMLSelectElement* selectElement = ownerSelectElement())
         return selectElement->formOwner();
 
     return 0;
 }
 
 } // namespace WebCore