1. Make |output_period_ms_| optional, so as to clarify where
it gets assigned a value. (I.e. the value set by the ctor
is not retained.)
2. Some extra const modifiers.
Bug: webrtc:8111
Change-Id: I9f3ad7ff763cfbc9c9385f7fd4325ba696772765
Reviewed-on: https://webrtc-review.googlesource.com/c/112588
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25877}
e7673cf922