Fix BWE bug where audio has timestamps in us.

The BWE expects arrival timestamps in ms, while the audio path delivered
them in us, causing the BWE to break down under the combined audio/video
BWE experiment. This was introduced in r9892 (https://chromium.googlesource.com/external/webrtc/+/68786d20400f1f3744ad83549325665c18ea9e5b).

BUG=webrtc:4758
R=mflodman@webrtc.org, sprang@webrtc.org

Review URL: https://codereview.webrtc.org/1360913004 .

Cr-Original-Commit-Position: refs/heads/master@{#10032}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 8bffba71072577ef8e81f48b615f231880de25a0
3 files changed