Used only by test code and by pseudo_tcp.
Bug: webrtc:6424
Change-Id: I28903e74f7b69cbdd8c368f4444c8a233eb76868
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128868
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27341}
