LayoutTest inspector/debugger/breakpoint-columns.html is a flaky timeout https://build.webkit.org/results/Apple%20Sierra%20Debug%20WK2%20(Tests)/r211990%20(1959)/results.html https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=inspector%2Fdebugger%2Fbreakpoint-columns.html
Marked test as flaky in http://trac.webkit.org/projects/webkit/changeset/212004