to support clients (e.g. RTCPReceiver) that collect and report RTT per sender ssrc.
Bug: webrtc:8239, webrtc:13853
Change-Id: I907fb35277b0f23bbe9f2cd2ef979ce0fb1f9338
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/257440
Reviewed-by: Emil Lundmark <lndmrk@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36439}