requestAnimationFrame passes a DOMHighResTimeStamp, polyfilling it

[kentaromiura]

rAF passes a DOMHighResTimeStamp (Performance.now()) or a DOMTimeStamp (Date.now()) if the prefixed version is used, since Performance.now() is not available, either using Date.now() or +new Date() should be enough, last one is known to work in any browser/server, so seems the best choice here even if it may be slower