where mutable access is required. Bug: webrtc:12334 Change-Id: I4b2b74f836aaf7f12278c3569d0d49936297716b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198846 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32936}