This reverts commit dc43cb24bd8ee85d6a8224c5928ceaf90de729b6. Reason for revert: Converted the wrong signal, should have been GatheringState. Original change's description: > Convert P2PTransportChannel Candidate Pair Change to CallbackList > > Earlier attempts have shown that this signal is multiply listened to. > > Bug: webrtc:11943 > Change-Id: If9130a7f4c70714b5afda5aca0469b66c8e2612f > Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/347981 > Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org> > Commit-Queue: Harald Alvestrand <hta@webrtc.org> > Cr-Commit-Position: refs/heads/main@{#42124} Bug: webrtc:11943 Change-Id: I73d5d815ced8d7aef4df765c9cf54d7637c6769d Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/348220 Commit-Queue: Harald Alvestrand <hta@webrtc.org> Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com> Cr-Commit-Position: refs/heads/main@{#42129}