LayoutTests for contentextensions seem to be very flaky https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fwebsocket%2Ftests%2Fhybi%2Fcontentextensions%2F https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fcontentextensions%2F stderr from the tests when they fail: 2016-10-04 14:26:08.235 WebKitTestRunner[25782:45468604] Extension compilation failed: Unspecified error during compile.
I'm not sure if each of these tests is flaky for their own reason, or if there is an underlying issue with the compilation of content extensions in general.
rdar://27788755
Marked as flaky in http://trac.webkit.org/projects/webkit/changeset/206914
Removed flaky expectation in https://trac.webkit.org/r224194
Talked to Alex about the tests further. Determined that tests should be marked as flaky: https://trac.webkit.org/changeset/225866/webkit