mListener = listener;
if (listener == nsnull) mListener = do_QueryInterface(request); else mListener = listener;
DataRequestForwarder::Init(nsIRequest *request, nsIStreamListener *listener){    mRequest  = request;    mChannel  = do_QueryInterface(request);    mListener = listener;        if (!mRequest || !mChannel || !mListener)        return NS_ERROR_FAILURE;        return NS_OK;}