The following layout test is failing on GTK media/video-volume-slider-drag.html Probable cause: This test is added at https://bugs.webkit.org/show_bug.cgi?id=137805 This could be timing issue. Test result: https://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20%28Tests%29/r174972%20%283637%29/media/video-volume-slider-drag-pretty-diff.html
Fixed bug. Committed r200126: <http://trac.webkit.org/changeset/200126>