I have been having the same problem. I used the "omnibox-popup" workaround...doesn't work. I clear history. Doesn't work. Uncheck "suggestion service." Does NOT work. Seriously, now, folks. I've been using (and loving) chrome for a while. This seems relatively new, though, and I really don't like it. Even when history is cleared, old searches and old visited pages show up in the omnibar (i.e., NOT just things from my bookmarks, which would be bad enough)???? This is just bad business, and makes me want to abandon chrome. (By the way, I am NOT actually an idiot...I've done all the easy things, and short of getting new programs or using command boxes to mess with the chrome files, I'm stymied.)
Seriously, Chrome developers. Fix this one right away, and don't make new and unneeded updates until it is done.