RtpVideoSender now stores fec type and overhead instead of querying the generator all the time. Setting of protection parameters and asking for current bitrate is also now handled just by the VideoFecGenerator instance, instead of going via RtpVideoSender. Finally, adds method to query for RtpState in VideoFecGenerator interface. This avoids an ugly cast that would have been even more trouble after moving fec generation. For context, see https://webrtc-review.googlesource.com/c/src/+/173708 Bug: webrtc:11340 Change-Id: Ia5e6cd919e71850c9cc5ed5a4f4417338d577162 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/174203 Commit-Queue: Erik Språng <sprang@webrtc.org> Reviewed-by: Sebastian Jansson <srte@webrtc.org> Cr-Commit-Position: refs/heads/master@{#31166}