nsCOMPtr<nsIInterfaceRequestor> callbacks; mStreamChannel->GetNotificationCallbacks(getter_AddRefs(callbacks));
nsresult rv = NS_ERROR_UNEXPECTED; nsCOMPtr<nsIWebNavigation> webNav; GetInterfaceFromChannel(mStreamChannel, NS_GET_IID(nsIWebNavigation), getter_AddRefs(webNav));
nsresult nsJSChannel::StopAll(){    nsCOMPtr<nsIInterfaceRequestor> callbacks;    mStreamChannel->GetNotificationCallbacks(getter_AddRefs(callbacks));    nsresult rv = NS_ERROR_UNEXPECTED;    nsCOMPtr<nsIWebNavigation> webNav(do_GetInterface(callbacks));    NS_ASSERTION(webNav, "Can't get nsIWebNavigation from callbacks!");    if (webNav) {        rv = webNav->Stop(nsIWebNavigation::STOP_ALL);    }    return rv;}