<http://webkit.org/b/75403>

Reviewed by Anders Carlsson.

Keep two maps of name -> RefPtr<HTMLNameCollection> on Document. We already
had maps for the CollectionCaches and were creating the HTMLNameCollections
every time they were accessed. We now let the collections create and manage
the CollectionCaches instead of Document.

No new tests since these collections are not exposed to the web.

* dom/Document.h:
* dom/Document.cpp:
(WebCore::Document::windowNamedItems):
(WebCore::Document::documentNamedItems):

    Replace the name/CollectionCache maps by name/HTMLNameCollection maps.

* bindings/js/JSDOMWindowCustom.cpp:
(WebCore::namedItemGetter):
* bindings/js/JSHTMLDocumentCustom.cpp:
(WebCore::JSHTMLDocument::nameGetter):

    Pass names as AtomicStrings to Document's collection getters.

* html/HTMLNameCollection.h:
(WebCore::HTMLNameCollection::create):
* html/HTMLNameCollection.cpp:
(WebCore::HTMLNameCollection::HTMLNameCollection):

    Store the name in an AtomicString instead of a String, incidentally
    making traversal of HTMLNameCollections more efficient.

* html/CollectionType.h:

    Remove two now-unneeded constants.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@103865 268f45cc-cd09-0410-ab3c-d52691b4dbfc