That test performs a seek then play() and wait 2 seconds for the ended event. On slow machines the media engine of the gtk port can take time to complete the seek. I think we should wait the end of the seek by waiting the "seeked" event and then fire the timer.
Created attachment 47013 [details] Refactored the test to use the seeked event.
fyi, typo in changelog: flacky
Comment on attachment 47013 [details] Refactored the test to use the seeked event. Nice change! r=me with David's suggested spelling fix
Landed as r53612. Thanks!