This adds support to enable message interleaving in the stream scheduler
from the socket, proxied by the send queue.
It also adds socket unit tests to ensure that prioritization and
interleaving works. Also, send queue test has been added to validate the
integration of the stream scheduler. But the actual scheduling parts of
it will be tested in the stream scheduler unit tests.
Bug: webrtc:5696
Change-Id: Ic7d3d2dc28405c77a107f0148f0096882961eec7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262248
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37355}