1async_test( t=> { 2 for (let i = 0; i < 50; i++) 3 performance.mark('foo' + i); 4 let marksCreated = 50; 5 let marksReceived = 0; 6 new PerformanceObserver(list => { 7 marksReceived += list.getEntries().length; 8 if (marksCreated < 100) { 9 performance.mark('bar' + marksCreated); 10 marksCreated++; 11 } 12 if (marksReceived == 100) 13 t.done(); 14 }).observe({type: 'mark', buffered: true}); 15}, 'PerformanceObserver with buffered flag should see past and future entries.'); 16