This test fails pretty frequently, no known regression point. https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported%2Fw3c%2Fweb-platform-tests%2Ffetch%2Fapi%2Fresponse%2Fresponse-trailer.html -FAIL trailer() test promise_test: Unhandled rejection with value: object "TypeError: undefined is not an object (evaluating 'res.trailer.then')" +FAIL trailer() test assert_equals: expected (object) null but got (string) "Trailer header value"
Marked as flaky in <http://trac.webkit.org/r214929> For whatever reason, this only happens on El Capitan bots now.
Closing. El Capitan expectations have been removed.
<rdar://problem/43118223>