The fast/regions/clip-to-padding-box-vertical-lr.html reftest is failing. The offending commit is not known. The difference in image outputs is really small, just a few pixels not being rendered in the letter 'p' in 'top: 4' in the middle square. http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fregions%2Fclip-to-padding-box-vertical-lr.html
CSS Regions were removed in Bug 174978.