The media/progress-events-generated-correctly.html layout test is flaky on GTK+. It's marked as TIMEOUT but it fails sometimes.
Updating test expectations on bug 143701.
Since a while ago this has been failing as timeout, but since r218270 the timeout was increased and it's now failing as Failure.
And now it's flaky again!
And now besides failing it's also timing out. Updating expectations.