Following [1], add many more checks for safe access to member variables. This change is effectively a no-op, but landed separately from the earlier change that's smaller but contains a fundamental assumption gleaned from the implementation (and its use). [1]: https://webrtc-review.googlesource.com/c/src/+/249942 Bug: webrtc:11988 Change-Id: I1568e2160c9faa6993c5b68044312f83d00e4815 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/249943 Auto-Submit: Tomas Gunnarsson <tommi@webrtc.org> Reviewed-by: Niels Moller <nisse@webrtc.org> Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org> Cr-Commit-Position: refs/heads/main@{#35850}