Re: [dom] High resolution timing for events (#23)

We (@majido) are [working on this in blink too](https://code.google.com/p/chromium/issues/detail?id=160524).  There are two completely different things coupled together here:

1. Use logical event time instead of strict "event creation time".
2. Use a monotonic/high-precision time (`DOMHighRestTimestamp`) instead of an epoch time.

It's 1 that's most important IMHO, giving us two key properties:
- Ability to accurately compute pointer velocity
- A basic way to measure input latency (very important for tracking improvements to some class of perf problems IMHO).
But it's also potentially hardest to spec.  Eg. does the spec currently require that events are delivered in increasing timestamp order?  If we rely on OS/device timestamps then it's possible, for example, that a `touchmove` may be dispatched after a `mousemove` with a later timestamp.

[WebKit has done 1 without 2](https://bugs.webkit.org/show_bug.cgi?id=117179) for a couple years now, but it's a kludge.  Given the lack of use cases for an epoch-based event timestamp and the existing lack of interoperability here, I agree we should also try to change the semantics of `timestamp`.

---
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/dom/issues/23#issuecomment-142292155