https://html.spec.whatwg.org/multipage/browsers.html#joint-session-history

The current idea here is to create a HistoryIterator that will lazily interleave Frame history depending on the NavigartionDirection. Each Frame entry will now also hold an Instant so the order of navigations can be determined.

cc @asajeffrey