LayoutTest http/tests/contentextensions/invalid-selector.html is a flaky image failure https://build.webkit.org/results/Apple%20Sierra%20Release%20WK2%20(Tests)/r211978%20(3440)/results.html https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fcontentextensions%2Finvalid-selector.html Link to images and diff: https://build.webkit.org/results/Apple%20Sierra%20Release%20WK2%20(Tests)/r211978%20(3440)/http/tests/contentextensions/invalid-selector-diffs.html
Marked test as flaky in http://trac.webkit.org/projects/webkit/changeset/211996