1promise_test(() => { 2 // The first promise waits for one buffered flag observer to receive 3 entries. 3 const promise1 = new Promise(resolve1 => { 4 let numObserved1 = 0; 5 new PerformanceObserver((entryList, obs) => { 6 // This buffered flag observer is constructed after a regular observer detects a mark. 7 new PerformanceObserver(list => { 8 numObserved1 += list.getEntries().length; 9 if (numObserved1 == 3) 10 resolve1(); 11 }).observe({type: 'mark', buffered: true}); 12 obs.disconnect(); 13 }).observe({entryTypes: ['mark']}); 14 performance.mark('foo'); 15 }); 16 // The second promise waits for another buffered flag observer to receive 3 entries. 17 const promise2 = new Promise(resolve2 => { 18 step_timeout(() => { 19 let numObserved2 = 0; 20 // This buffered flag observer is constructed after a delay of 100ms. 21 new PerformanceObserver(list => { 22 numObserved2 += list.getEntries().length; 23 if (numObserved2 == 3) 24 resolve2(); 25 }).observe({type: 'mark', buffered: true}); 26 }, 100); 27 performance.mark('bar'); 28 }); 29 performance.mark('meow'); 30 // Pass if and only if both buffered observers received all 3 mark entries. 31 return Promise.all([promise1, promise2]); 32}, 'Multiple PerformanceObservers with buffered flag see all entries'); 33