This allows clients to move to these new accessors and off of the sync_label field which is deprecated. Bug: webrtc:7932 Change-Id: I32b30087bf1be380d607a649bd90fa9617dafeb9 Reviewed-on: https://webrtc-review.googlesource.com/58020 Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org> Commit-Queue: Steve Anton <steveanton@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22213}