Returns the number of milliseconds that has elapsed since the time origin, if
the runtime does not support the performance API it will fallback to return
the number of milliseconds since the unix epoch.
Returns number
The number of milliseconds as a DOMHighResTimeStamp double value or
an integer depending on the runtime.
Returns the number of milliseconds that has elapsed since the time origin, if the runtime does not support the
performanceAPI it will fallback to return the number of milliseconds since the unix epoch.