Prerequisite: have an input string which, when typed in the omnibox, will show a dropdown with an associated keyword on some row other than the first one.

STR:
(1) Type this input.
(2) Tab to the row with the associated keyword.
(3) If you now hit <esc>, you'll reset your tabbing and be back on the first result.  This is expected.
(4) If instead you <tab> once more, so you're in associated keyword mode, and then hit <esc>, you'll reset out of editing entirely, back to the "no input in progress" state.  This should have done the same thing as step 3.