nsCOMPtr<nsIAtom> media(dont_AddRef(NS_NewAtom(aNewMedium)));
nsCOMPtr<nsIAtom> media = do_GetAtom(aNewMedium);
DOMMediaListImpl::Append(const nsAString& aNewMedium){  if (aNewMedium.IsEmpty())    return NS_ERROR_DOM_NOT_FOUND_ERR;  nsCOMPtr<nsIAtom> media(dont_AddRef(NS_NewAtom(aNewMedium)));  NS_ENSURE_TRUE(media, NS_ERROR_OUT_OF_MEMORY);