Under the combined network/worker thread project, tasks
are unnecessarily posted to the same thread.
This CL reaps 90% overhead savings in sent packet feedback
as measured with Perfetto under a 49p Meet call.
The identity of the posted calls was uncovered with WebRTC/Chrome's
new location-aware tracing.
TESTED=presubmit + local Meet calls.
Bug: chromium:1373439
Change-Id: I0c43aa4de884831838747d52b21c45fd360106e8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/295780
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Markus Handell <handellm@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39484}