And change nsGeoPosition to store DOMTimeStamp instead of long long because it is a more descriptive type. DOMTimeStamp is a typedef for uint64_t, so we're not losing any precision using DOMTimeStamp instead of long long.
MozReview-Commit-ID: hjXnw959yC
nsGeoPositionCoords will convert NaNs returned from the location providers to null properties of the JavaScript Coordinates object.
MozReview-Commit-ID: Cmuf2aO0ClD