Chrome actually keeps it in the database. However it only works within a single browser and breaks as soon as you're leaving for a native app, note in your todo list, etc. So I feel like correlating timestamps is the way to go here, simple enough and agnostic of specific implementations.
I'm talking mostly about normal tabs in normal desktop browsers. When you open a new tab, it should keep the "Back" history of its parent.
Safari for iOS, too, has a feature where you can temporarily go "Back" from new tabs. But like you said it breaks if you do anything else. Kind of a hack for mobile convenience rather than a true feature.
