The Layout test media/media-source/media-source-small-gap.html timeouts on the GTK port since it was added on r202829: <http://trac.webkit.org/changeset/202829>
Marked as timing out in https://trac.webkit.org/changeset/203509/trunk/LayoutTests/platform/gtk/TestExpectations
Fixed by #164022 on http://svn.webkit.org/repository/webkit/trunk@209797