This field was only used in RTP Data Channels and isn't needed anymore. Bug: webrtc:6625 Change-Id: Ieaa7ae03ca3e90eb4ddec4d384f5a76cef1600cc Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/215687 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Florent Castelli <orphis@webrtc.org> Cr-Commit-Position: refs/heads/master@{#33791}