Sebastian Jansson 84848f26b5 Adds interfaces for audio and video engines.
This makes the currently implicit interfaces explicit and
prepares for making CompositeMediaEngine non-templated.

Bug: webrtc:9883
Change-Id: I57452acc9ada60a801f6d624894440a942c12ded
Reviewed-on: https://webrtc-review.googlesource.com/c/106940
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25667}
2018-11-16 10:10:36 +00:00
..
2018-06-19 14:00:39 +00:00
2018-06-19 14:00:39 +00:00
2017-10-31 17:46:42 +00:00