Since it's now always a tabbrowser... I think this code dates back to when there wasn't a tabbrowser.
Created attachment 244804 [details] [diff] [review] patch It's difficult to resist the urge to clean up openLocation.js, but in the interests of quick review I'll file another bug for that :)
Comment on attachment 244804 [details] [diff] [review] patch r=mano
mozilla/browser/base/content/browser.js 1.734 mozilla/browser/base/content/openLocation.js 1.11