Use fake audio device in peerconnectioninterface_unittest.cc.

This test doesn't actually send/receive any audio; it's only testing
the interface layer. But the fact that it was creating/destroying real
audio devices repeatedly caused problems when tests were run in
parallel. So switching to a fake audio device solves this.

BUG=webrtc:7806

Review-Url: https://codereview.webrtc.org/2997383002
Cr-Original-Commit-Position: refs/heads/master@{#19472}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: d7850b299bed6af1598800b051c9efda155d97b0
1 file changed