rv = NS_NewChannel(getter_AddRefs(channel), uri, loadGroup, notificationCallbacks, loadFlags);
rv = NS_NewChannel(getter_AddRefs(channel), uri, ioService, loadGroup, notificationCallbacks, loadAttributes);
NS_OpenURI(nsIInputStream **result,           nsIURI *uri,           nsILoadGroup *loadGroup,           nsIInterfaceRequestor *notificationCallbacks,           PRUint32 loadFlags){    nsresult rv;    nsCOMPtr<nsIChannel> channel;    rv = NS_NewChannel(getter_AddRefs(channel), uri,                       loadGroup, notificationCallbacks, loadFlags);    if (NS_FAILED(rv)) return rv;    nsIInputStream *inStr;    rv = channel->Open(&inStr);    if (NS_SUCCEEDED(rv))        *result = inStr;    return rv;}