nsCOMPtr<nsIAtom> tag; aElement->GetTag(getter_AddRefs(tag));
nsXULContentBuilder::CloseContainer(nsIContent* aElement){    // See if we're responsible for this element    if (! IsElementInBuilder(aElement, this))        return NS_OK;    nsCOMPtr<nsIAtom> tag;    aElement->GetTag(getter_AddRefs(tag));    return NS_OK;}