and add implementation comment Bug: webrtc:8239 Change-Id: Id24937018d386e386b8241aca8f5d686e7cc527a Reviewed-on: https://webrtc-review.googlesource.com/26600 Reviewed-by: Niels Moller <nisse@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#20925}