These checks replace the need for a mutex as the usage of the StreamInterface methods is consistently on the same thread as the callbacks. Bug: none Change-Id: I0c5aaddcbdaa4a6a84c3bc73306563a9f8a8821d Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/347902 Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#42148}