These classes moved to rtp_rtcp_defines.h: BitrateStatisticsObserver SendSideDelayObserver SendPacketObserver Bug: webrtc:5876 Change-Id: I38861f8de555aff0b22e7a67a5ac0090a5e98d4e Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/135464 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Commit-Queue: Niels Moller <nisse@webrtc.org> Cr-Commit-Position: refs/heads/master@{#27870}