Call send statistic updates are initiated on the send
transport sequence which forced calls to PostTask to the
worker thread which keeps several related attributes
protected by it.
Change this by:
* Using std::atomics for three attributes where synchronization
doesn't really matter and which can be accessed on either
context.
* Introducing a thread-compatible internal class which keeps
the statistics protected by the send transport sequence, and
emits UMA statistics on destruction.
The change also achieves the following trivial changes:
* The call origin time is now tracked by a proper
webrtc::Timestamp.
* The explicit use of the |send_transport_queue_| was replaced by
a more relaxed sequence checker.
Bug: webrtc:11993
Change-Id: I428a4d98b5fd2fd31222f62e597a9d61a3d4899f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/220931
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34187}
d99430410b