chrome on osx: remove specific sites from autocomplete

No, not because I don't want people to see my love of "goatsdoingnaughtythings.com" when I start typing "google", but because now I was annoyed that "amazon.co.uk" kept showing up when I started typing "amazon" -- anyway, to remove an autosuggestion on OSX chrome, make sure it's highlighted in the list and hit fn-shift-delete.