[webrtc-pc] getSelectedCandidatePair needs special treatment for PRFLX candidates (#2134)

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

== getSelectedCandidatePair needs special treatment for PRFLX candidates ==
getSelectedCandidatePair is potentially exposing a used PRFLX candidate.
Given that it does not come from SDP/addIceCandidate, it might contain information not know from the web application, like the IP address.
This should be concealed like done for WebRTC stats.

Also, PRFLX candidates do not have an SDP equivalent, which makes it not straightforward to populate some of RTCIceCandidate properties like 'candidate'.
The spec should describe this.

Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/2134 using your GitHub account