This is a weird one... sending to Pavel as a devtools person in hopes he has more idea of how to triage than I do. See http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20-%20chromium.org&tests=http%2Ftests%2Fxmlhttprequest%2Forigin-whitelisting-https.html&showExpectations=true We sometimes print "line 57:" or "line 58:" after the "CONSOLE MESSAGE:". Otherwise the test appears to pass.