Submit pages onbeforeunload?

[da2x]

The content script can set a variable stating when the page was loaded (activity started time), and submit pages with sendMessage in onbeforeunload (activity stopped time) instead of guesstimating at 30-seconds. I'm not sure of this is better than just saying 30 seconds, though. I’m unclear exactly how Windows Timeline use/present this data. Based on some experiments with Edge, it would seem that long-lived tabs/activities are prioritized over shorter-lived tabs when Timeline summarizes a day and compresses it down to a few entries. This could mean webmail would be the number one item for most days for most users, but I suspect that Timeline will prioritize more unique activities (unconfirmed; it’s not like there is any documentation on any of this – but I’m not seeing Tweetdeck and webmail stand out in my own Timeline).