The mathml/presentation/mspace-units.html layout test is failing ever since the simple line layout was enabled on the GTK port. http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fmulticol%2Fseamless-flowed-through-columns.html http://trac.webkit.org/changeset/158102
Fixed per bug 124128.