nsITransportEventSink Interface

 Transport status notification.

 @param aTransport
        the transport sending this status notification.
 @param aStatus
        the transport status (resolvable to a string using
        nsIErrorService). See nsISocketTransport for socket specific
        status codes and more comments.
 @param aProgress
        the amount of data either read or written depending on the value
        of the status code.  this value is relative to aProgressMax.
 @param aProgressMax
        the maximum amount of data that will be read or written.  if
        unknown, 0xFFFFFFFF will be passed.