This will make code using RtpSequenceNumberMap simpler. Bug: webrtc:10501 Change-Id: I74b11f3562d5962efb42b5bb7662489d7d411388 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/131386 Commit-Queue: Elad Alon <eladalon@webrtc.org> Reviewed-by: Niels Moller <nisse@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#27485}