It has been suggested that the cause of the failure is that the necessary (non free) codecs are not installed on the build bots.
Test added in: http://trac.webkit.org/changeset/76621
Original bug: https://bugs.webkit.org/show_bug.cgi?id=52467
Test added to LayoutTests/platform/gtk/Skipped in: https://trac.webkit.org/changeset/76640
Created attachment 80188 [details]
The codecs are installed on the buildbots (gst-ffmpeg), the issue is just that the GStreamer player didn't handle the audio/x-m4a mimetype correctly.
Comment on attachment 80188 [details]
Thanks for the quick fix!
Committed r76773: <http://trac.webkit.org/changeset/76773>
Will send a new patch as the first one broke some tests, sorry :(
Created attachment 80315 [details]
Ping? Martin? :)
Committed r77494: <http://trac.webkit.org/changeset/77494>
http://trac.webkit.org/changeset/77494 might have broken GTK Linux 32-bit Debug