Waits to start the channel until a message is received. This should only
be used on the end that is started first: Such as an iframe parent, a
worker's host, or a tab's creator.
Optional keep_alive_interval
keep_alive_interval:undefined | number
The interval with which to send keep-alives. This must be shorter than the
timeout interval on the receiving end.
Optional timeout
timeout:undefined | number
If a keepalive has not been received for this much time, assume that this
RpcChannel has been closed.
Waits to start the channel until a message is received. This should only be used on the end that is started first: Such as an
iframeparent, a worker's host, or a tab's creator.