*aResult = new nsXBLService; if (!*aResult)
nsXBLService* result = new nsXBLService; if (! result)
NS_NewXBLService(nsIXBLService** aResult){  *aResult = new nsXBLService;  if (!*aResult)    return NS_ERROR_OUT_OF_MEMORY;  NS_ADDREF(*aResult);  return NS_OK;}