This reverts commit 9d230d54c7eef31ac1100f0aeef1374dd1ac62fa.
Reason for revert: Speculative revert to see if it's the cause of a few perf changes (some bad, some not so bad).
Bug: webrtc:13613
Original change's description:
> (Un/)Subscribe RtpVideoSender for feedback on the transport queue.
>
> * RtpVideoSender now registers/unregisters for feedback callback
> inside of SetActive(), which runs on the transport queue.
> * Transport feedback is given on the transport queue
> * Registration/unregistration for feedback is done on the same
> * Removed the last mutex from TransportFeedbackDemuxer.
>
> Ultimately, this work is related to moving state from the Call
> class, that's related to network configuration, but due to the code
> is currently written is attached to the worker thread, over to the
> Transport, where it's used (e.g. suspended_video_send_ssrcs_).
>
> Bug: webrtc:13517, webrtc:11993
> Change-Id: I057d0e2597e6cb746b335e0308599cd547350e56
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/248165
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#35777}
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: webrtc:13517, webrtc:11993
Change-Id: I824623b3b1c14f0ca7049a2a0890c6d97b7fb608
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/249600
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35815}
7734fc64b9