Note: This feature is only available in Web Workers.
The performance property of the WorkerGlobalScope interface returns a Performance object, which can be used to gather performance information about code running in the worker's scope.
Performance entries are per context. If you create a mark on a worker thread, you will not see it in the main thread or any other workers.
Note that only the following performance interfaces are available in worker contexts:
PerformancePerformanceEntryPerformanceMarkPerformanceMeasurePerformanceObserverPerformanceObserverEntryListPerformanceResourceTimingPerformanceServerTimingA Performance object offering access to performance and timing-related information for the context it is called on.