It exposes statistics about the event loop utilization.
<number>
The idle value in the object returned by performance.eventLoopUtilization() during the sampleInterval window.
<number>
The active value in the object returned by performance.eventLoopUtilization() during the sampleInterval window.
<number>
The utilization value in the object returned by performance.eventLoopUtilization() during the sampleInterval window.
<object>
Raw value returned by performance.eventLoopUtilization() during the sampleInterval window.