11cb0ef41Sopenharmony_ciasync_test(t => {
21cb0ef41Sopenharmony_ci  performance.mark('foo');
31cb0ef41Sopenharmony_ci  // Use a timeout to ensure the remainder of the test runs after the entry is created.
41cb0ef41Sopenharmony_ci  t.step_timeout(() => {
51cb0ef41Sopenharmony_ci    // Observer with buffered flag set to false should not see entry.
61cb0ef41Sopenharmony_ci    new PerformanceObserver(() => {
71cb0ef41Sopenharmony_ci      assert_unreached('Should not have observed any entry!');
81cb0ef41Sopenharmony_ci    }).observe({type: 'mark', buffered: false});
91cb0ef41Sopenharmony_ci    // Use a timeout to give time to the observer.
101cb0ef41Sopenharmony_ci    t.step_timeout(t.step_func_done(() => {}), 100);
111cb0ef41Sopenharmony_ci  }, 0);
121cb0ef41Sopenharmony_ci}, 'PerformanceObserver without buffered flag set to false cannot see past entries.');
13