Add a BWE fairness test.

Also moves the BWE perf tests to webrtc_perf_tests for tracking.

BUG=4548
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/45189004

Cr-Original-Commit-Position: refs/heads/master@{#9022}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 09bdc1e5f5a932ef4a20957470c088f0dfc145a8
5 files changed