Converts RtpDemuxerTest to use a test fixture which creates the
RtpDemuxer under test and wraps sink adding/observer adding
functions to automatically remove them at the end of the test case.
Bug: None
Change-Id: I7e40223f6837caa5443d9850477198c1f7a8d14a
Reviewed-on: https://chromium-review.googlesource.com/608906
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19400}
9e0c742f1b