It turned out that the negotiated rtp header extensions are not fully known in WebRtcVideoChannel::AddSendStream. The cl also remove the unnecessary factory for creating VideoStreamEncoder. Bug: webrtc:12000 Change-Id: If994c8deb69f3ce4212896d3ad757dac94c6e09f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198840 Reviewed-by: Erik Språng <sprang@webrtc.org> Commit-Queue: Per Kjellander <perkj@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32916}