OK, so I update my search preferences to make "wp" the Wikipedia key word. (I think, ok, maybe "w" was too short or something.)
Close the browser. Reopen. Check the options again. (Still there.) Type wp (so far so good, the Chrome hints drop-down looks like I'm going to hit Wikipedia) space, "San Francisco" (no quotes) ... and oops, the hints have changed to "Google Search" (as soon as I type the first character.