[webrtc-stats] Finding associated audio and video tracks? (#574)

WeichengSu has just created a new issue for https://github.com/w3c/webrtc-stats:

== Finding associated audio and video tracks? ==
According to the definition of `estimatedPlayoutTimestamp`, we can use `audioTrackStats.estimatedPlayoutTimestamp - videoTrackStats.estimatedPlayoutTimestamp` to get the AV sync. https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-estimatedplayouttimestamp

I have been using `trackIds` in `RTCMediaStreamStats` to find the associated audio and video tracks. https://w3c.github.io/webrtc-stats/#idl-def-rtcmediastreamstats
However, it's made obsolete. What's the recommended way to find the associated audio and video tracks without `RTCMediaStreamStats`?

Please view or discuss this issue at https://github.com/w3c/webrtc-stats/issues/574 using your GitHub account