dom-repeat docs don't say the units for the delay parameter

[davidmaxwaterman]

https://www.polymer-project.org/1.0/docs/api/elements/dom-repeat

delay : number 
When using a filter or sort function, the delay property determines a debounce time after a change to observed item properties that must pass before the filter or sort is re-run. This is useful in rate-limiting shuffing of the view when item changes may be frequent

and the same for 2.0 I notice:

https://www.polymer-project.org/2.0/docs/api/elements/Polymer.DomRepeat

I do notice the comment for the debouncer function in the code mentions ms :

https://github.com/Polymer/polymer/blob/master/lib/elements/dom-repeat.html#L457

I suppose ms would always be my a dev's first guess, but I don't think the dev should be expected to guess, or dig into the code to find this out.