Since https://webrtc-review.googlesource.com/c/src/+/228433 both audio and video now only call Get/SetRtpState while not registered to the packet router. We can thus remove the lock around packet sequencer and just use a thread checker. Bug: webrtc:11340 Change-Id: Ie6865cc96c36208700c31a75747ff4dd992ce68d Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228435 Commit-Queue: Erik Språng <sprang@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34755}