The following layout test is flaky on GTK [WebKit2] http/tests/w3c/webperf/submission/Google/resource-timing/html/test_resource_dynamic_insertion.html http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&showExpectations=true&tests=http%2Ftests%2Fw3c%2Fwebperf%2Fsubmission%2FGoogle%2Fresource-timing%2Fhtml%2Ftest_resource_dynamic_insertion.html
This test no longer exists. Closing bug.