Module Timer.Duration

type t =
  1. | Ok of Core.Time_ns.Span.t
  2. | Backgrounding_changed_unreliable of Core.Time_ns.Span.t

If the tab was backgrounded or unbackgrounded between the start and stop timestamp, the measured duration will be very unreliable.

Background status is determined by referencing Ui_metrics.Private.num_backgrounding_changes.

val sexp_of_t : t -> Sexplib0.Sexp.t