This is a testharness.js-based test.
Found 2 FAIL, 0 TIMEOUT, 0 NOTRUN.
[FAIL] idl_test setup
  promise_test: Unhandled rejection with value: "error: Action set_permission failed"
[FAIL] MIDIOutput interface: operation clear()
  assert_own_property: interface prototype object missing non-static operation expected property "clear" missing
Harness: the test ran to completion.