Tomas Gunnarsson 2e85b5fa51 Add a check for empty channels to ChannelManager dtor.
This is a necessary precondition for upcoming changes that will remove
calls to Invoke() that currently occur during construction/destruction
of media channel objects.

Subsequently fix RtpSenderReceiverTest to destroy channels that were
created in the constructor, in the destructor.

Bug: webrtc:11992
Change-Id: I526908d997d27495659805d84113c84c48568712
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/246680
Auto-Submit: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35702}
2022-01-16 16:13:53 +00:00
..
2021-11-29 12:18:29 +00:00
2019-01-28 11:17:00 +00:00
2021-08-31 14:27:49 +00:00
2021-05-27 09:56:42 +00:00