Also making some more state const.
Instances of this class are currently constructed and used on the
"worker thread" but as part of the work for bug webrtc:11993, the
instances will be moved over to the network thread. Since the
class as is does not require synchronization, that is a good property
to make explicit now and then make sure we maintain it in the
transition.
Bug: webrtc:11993
Change-Id: Id587a746ce0a4363b9e9871ae1749549f8ef3e24
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/202681
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33035}