This adds a stream scheduler using virtual finish time (as defined in
e.g. many Fair Queuing scheduler implementations), which indicates when
a stream's next sent packet is supposed to be sent.
In the initial version, this will be used to implement a round robin
scheduler, by emulating that a stream's virtual finish time - when
scheduled - is the "one more" than all existing virtual finish times.
That will make the scheduler simply iterate between the streams in
round robin order.
The stream scheduler component is tested in isolation, and follow-up
CLs will integrate it into the send queue.
Bug: webrtc:5696
Change-Id: Iaa2c204f9b9a00517f55355cb11cfd25bb415f9e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/261946
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37157}