When delta encoding, use ToUnsigned() and ToSigned() on
timestamp_ms, since it's a signed type. This is only relevant
for delta-encoding/decoding.
Bug: webrtc:8111
Change-Id: I1fabfcb2be64793c281f5bc0d38a2f8035dd0d18
Reviewed-on: https://webrtc-review.googlesource.com/c/110504
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25602}