LayoutTest inspector/indexeddb/clearObjectStore.html is a flaky timeout https://build.webkit.org/builders/Apple%20El%20Capitan%20Debug%20WK1%20(Tests)/builds/10919 https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=inspector%2Findexeddb%2FclearObjectStore.html
This appears to be limited to macOS debug.
Marked test as flaky on macOS debug in http://trac.webkit.org/projects/webkit/changeset/210902