Integration test that verifies that data channels open.
Integration test that verifies that data channels open.

This is in preparation for writing tests that verify that
they close, and that they close at the right times.

Bug: chromium:1030631, webrtc:10360
Change-Id: I8129a9fc9731c1bfe1a660e82e23c1aeff1e5087
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162181
Reviewed-by: Steve Anton <93f73658da16553b94c040887a439a155812e54e@webrtc.org>
Commit-Queue: Harald Alvestrand <ce816cd73d80f958d82de1df356058c2d2bca378@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#30091}

TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc