Definition
Performance Timeline defines PerformanceObserver
[Exposed=(Window,Worker)]
interface PerformanceObserver {
constructor(PerformanceObserverCallback callback);
undefined observe (optional PerformanceObserverInit options = {});
undefined disconnect ();
PerformanceEntryList takeRecords();
[SameObject] static readonly attribute FrozenArray<DOMString> supportedEntryTypes;
};