zhihuang 4dfb8cef51 Make the default value of rtcp-mux policy to required.
Change the default value of rtcp-mux policy in RTCConfiguration.
Refactor the peerconnectioninterface and webrtcsession unit tests.

BUG=webrtc:6030

Review-Url: https://codereview.webrtc.org/2043193003
Cr-Commit-Position: refs/heads/master@{#15217}
2016-11-23 18:30:21 +00:00
..
2016-02-10 09:53:26 +00:00