The fast/backgrounds/background-opaque-clipped-gradients.html layout test is failing on GTK+ since r177658 (https://trac.webkit.org/changeset/r177658). The test expects that the border should be under one part of the gradient. Which is weird. https://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20%28Tests%29/r181476%20%286927%29/fast/backgrounds/background-opaque-clipped-gradients-diffs.html
fast/backgrounds/background-opaque-clipped-gradients.html layout test was being skipped. Passing again after <http://trac.webkit.org/changeset/r191658>. Unskipped in <http://trac.webkit.org/changeset/194218>.