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Test Info: Warnings

// META: script=resources/utils.js
async_test(t => {
assert_implements(window.PerformanceLongTaskTiming, 'Longtasks are not supported.');
new PerformanceObserver(t.step_func((entryList, obs) => {
const observer = new PerformanceObserver(t.step_func_done(list => {
let longtaskObserved = false;
list.getEntries().forEach(entry => {
if (entry.entryType === 'mark')
return;
checkLongTaskEntry(entry);
longtaskObserved = true;
});
assert_true(longtaskObserved, 'Did not observe buffered longtask.');
}));
observer.observe({type: 'longtask', buffered: true});
// Observer mark so that we can flush the observer callback.
observer.observe({type: 'mark'});
performance.mark('m');
// Disconnect the embedding observer so this callback only runs once.
obs.disconnect();
})).observe({entryTypes: ['longtask']});
// Create a long task.
const begin = window.performance.now();
while (window.performance.now() < begin + 60);
}, 'PerformanceObserver with buffered flag can see previous longtask entries.');