If the real-time clock makes a sudden and large shift forward while
there is at least one packet in the queue, the pacer would previously
try to "replay" the behavior it would have done while it was asleep.
This can lead to grand bursts of padding packets, which is
undesireable.
This CL mitigates this problem by forwarding the internal state clock
to (now - 50ms) if there is nothing to do but generate padding.
Bug: webrtc:11340, b/258509536
Change-Id: I5b8a130d938dd2566f72c1946c139f50e099e5a9
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/285380
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38752}