It's put in the public folder since the intention is to expose it in
SendOptions.
Additionally, use TimeMs::InfiniteFuture() to represent sending a
message with no limited lifetime (i.e. to send it reliably).
One benefit for these two is avoiding using absl::optional more than
necessary, as it results in larger struct sizes for the outstanding
data chunks.
Bug: webrtc:12943
Change-Id: I87a340f0e0905342878fe9d2a74869bfcd6b0076
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/235984
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35323}