In theory, Chrome sends your entire browsing history over to Google, since its unified omnibar doesn't distinguish between searching and typing in location. Firefox (and any browser that separates the location and search bar) doesn't have this problem.
To be frank I'm not sure how Google uses this information, but it does make me laugh when the whole Ubuntu Dash searches Amazon thing blew up. It's the same thing, really, yet nobody talks about Chrome at all.