imported/w3c/web-platform-tests/XMLHttpRequest/setrequestheader-header-allowed.htm is flaky on GTK. PASS XMLHttpRequest: setRequestHeader() - headers that are allowed (Authorization) -PASS XMLHttpRequest: setRequestHeader() - headers that are allowed (Pragma) +FAIL XMLHttpRequest: setRequestHeader() - headers that are allowed (Pragma) assert_equals: expected "Pragma," but got "pragma," FAIL XMLHttpRequest: setRequestHeader() - headers that are allowed (User-Agent) assert_equals: expected "User-Agent," but got "" FAIL XMLHttpRequest: setRequestHeader() - headers that are allowed (Content-Transfer-Encoding) assert_equals: expected "Content-Transfer-Encoding," but got "" PASS XMLHttpRequest: setRequestHeader() - headers that are allowed (Content-Type) The problem is as old as there is data on GTK. Failure rate is quite high. https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&revision=222541&tests=imported%2Fw3c%2Fweb-platform-tests%2FXMLHttpRequest%2Fsetrequestheader-header-allowed.htm
Updated expectations in r222572. Please update accordingly when this issue is resolved.