The additional structs are not used anywhere yet. Bug: webrtc:8653 Change-Id: I8b3891e7f8d92286ffd43ea6010258a5828fa3b8 Reviewed-on: https://webrtc-review.googlesource.com/35007 Commit-Queue: Zach Stein <zstein@webrtc.org> Reviewed-by: Seth Hampson <shampson@webrtc.org> Reviewed-by: Peter Thatcher <pthatcher@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21682}