I'll just chime in here- I've done extensive work on Google Chrome forensics and I am not kidding when I say it tracks everything, not just the URL and time. And unlike Internet Explorer, which stores the last 2 times you visited the page, Chrome stores every single visit you made to every page. It also stores what resources each page loaded (the cache) and keeps track of when they were stored and when they were accessed.

Chrome also knows every single piece of browser history, including how you got to the current page- was it a redirect, a link click, typed into the Omnibar, autocompleted from the Omnibar, &c. It knows which visit spawned your current visit to this page. It also knows how long you've spent on each page visit, and therefore how long you spent on the previous site.

With all those things (and more, but I'm still testing and writing that up), you can piece together a very good image of the user's history, particularly since Chrome tracks timestamps down to the microsecond. The actual stored resolution I believe is limited by system calls, but millisecond resolution is typical. From this information I have reconstructed user activity in cases where timing and intention are crucial.

... ladies, I'm single!