This test sometimes times out on both GTK and WPE.
It seems that under stress, this test can cause a deadlock and sending the FLUSH_STOP event in WebKitMediaSrc. It seems similar to what happens in media/media-source/media-source-abort-resets-parser.html, although in the latter it happens more easily.
(In reply to Carlos Bentzen from comment #1) > can cause a deadlock and sending the can cause a deadlock when sending*