This is a testharness.js-based test.
Found 8 FAIL, 0 TIMEOUT, 0 NOTRUN.
[FAIL] PerformanceLongTaskTiming interface: attribute startTime
  assert_own_property: expected property "startTime" missing
[FAIL] PerformanceLongTaskTiming interface: attribute duration
  assert_own_property: expected property "duration" missing
[FAIL] PerformanceLongTaskTiming interface: attribute name
  assert_own_property: expected property "name" missing
[FAIL] PerformanceLongTaskTiming interface: attribute entryType
  assert_own_property: expected property "entryType" missing
[FAIL] TaskAttributionTiming interface: attribute startTime
  assert_own_property: expected property "startTime" missing
[FAIL] TaskAttributionTiming interface: attribute duration
  assert_own_property: expected property "duration" missing
[FAIL] TaskAttributionTiming interface: attribute name
  assert_own_property: expected property "name" missing
[FAIL] TaskAttributionTiming interface: attribute entryType
  assert_own_property: expected property "entryType" missing
Harness: the test ran to completion.