Rename CollectionIndexCache API to not use 'Element'

Source/core/html/HTMLCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003-2008, 2011, 2012, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. 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 310 matching lines @@
         || element.hasTagName(formTag)
         || element.hasTagName(frameTag)
         || element.hasTagName(framesetTag)
         || element.hasTagName(iframeTag)
         || element.hasTagName(imgTag)
         || element.hasTagName(inputTag)
         || element.hasTagName(objectTag)
         || element.hasTagName(selectTag);
 }
 
-Element* HTMLCollection::traverseToFirstElement() const
+Element* HTMLCollection::traverseToFirst() const
 {
     switch (type()) {
     case HTMLTagCollectionType:
         return ElementTraversal::firstWithin(rootNode(), makeIsMatch(toHTMLTagCollection(*this)));
     case ClassCollectionType:
         return ElementTraversal::firstWithin(rootNode(), makeIsMatch(toClassCollection(*this)));
     default:
         if (overridesItemAfter())
             return virtualItemAfter(0);
         if (shouldOnlyIncludeDirectChildren())
             return ElementTraversal::firstChild(rootNode(), makeIsMatch(*this));
         return ElementTraversal::firstWithin(rootNode(), makeIsMatch(*this));
     }
 }
 
-Element* HTMLCollection::traverseToLastElement() const
+Element* HTMLCollection::traverseToLast() const
 {
     ASSERT(canTraverseBackward());
     if (shouldOnlyIncludeDirectChildren())
         return ElementTraversal::lastChild(rootNode(), makeIsMatch(*this));
     return ElementTraversal::lastWithin(rootNode(), makeIsMatch(*this));
 }
 
 Element* HTMLCollection::traverseForwardToOffset(unsigned offset, Element& currentElement, unsigned& currentOffset) const
 {
     ASSERT(currentOffset < offset);
@@ skipping 145 matching lines @@
 }
 
 void HTMLCollection::trace(Visitor* visitor)
 {
     visitor->trace(m_namedItemCache);
     visitor->trace(m_collectionIndexCache);
     LiveNodeListBase::trace(visitor);
 }
 
 } // namespace blink