RTCDataChannel onopen is not compliant #46
Description
The open event emitted by RTCDataChannel instances is not compliant with the spec. It should be an instance of https://developer.mozilla.org/en-US/docs/Web/API/RTCDataChannelEvent, which has a channel property pointing to the "source" channel.
Instead, I'm observing a plain { type: "open" } object being emitted. I think the relevant code is this. I suspect there was supposed to be some wrapper code on the JS side to construct a proper instance of RTCDataChannelEvent.