DevTools: do not consider ? a shortcut while editing.

BUG=425451
R=vsevik@chromium.org

Review URL: https://codereview.chromium.org/659403006

git-svn-id: svn://svn.chromium.org/blink/trunk@184173 bbb929c8-8fbe-4397-9dbb-9b2b20218538