As part of trying to improve our web-platform-test coverage I took a look at the mediacapture-stream tests. This was the only one I couldn't get passing or failing reliably - it seems to just timeout without any obvious errors being raised (checked for lots of different events, but I don't know much about MediaStream so maybe I just wasn't looking in the right place for completion/error events).
The test passes fine when I run it in Chrome canary: https://w3c-test.org/mediacapture-streams/MediaStreamTrack-MediaElement-disabled-audio-is-silence.https.html
So the timeout has something to do with the special configuration in content_shell.
Comment 1 by bugdroid1@chromium.org
, Feb 24 2017