[kjennison]

Good question! This comes from requesting Chrome's tabs API: https://developer.chrome.com/extensions/tabs

The extension doesn't track your history (or even read from it, currently). We'll likely eventually implement a "Top Sites" feature that will replicate some of Chrome's new tab functionality, at which point we'll give users the ability to opt in to have the extension use their history to display their top sites on the new tab page.