Similar to the getter method (see
https://webrtc-review.googlesource.com/83123), this is a preparation
for inheriting the method from the base class, and delete the
corresponding redundant timestamp member.
Bug: webrtc:9378
Change-Id: Idbb48e7058c94d6d4aa9a2b19e608ef08c2e35b4
Reviewed-on: https://webrtc-review.googlesource.com/83726
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23665}
7e9a619599