This is a testharness.js-based test. FAIL Test MessageEvent supplants ServiceWorkerMessageEvent. assert_equals: ServiceWorkerMessageEvent assert_unreached: unregister should not be defined. expected (undefined) undefined but got (function) function "function ServiceWorkerMessageEvent() { [native code] }" fail: Failed to get a ServiceWorkerRegistration: The URL protocol of the current origin ('file://') is not supported. Reached unreachable code Harness: the test ran to completion.