DevTools: Ctrl + [1-9] on Numpad should switch panels, too

R=aandrey, eustas, vsevik
BUG=324412

Review URL: https://codereview.chromium.org/115243002

git-svn-id: svn://svn.chromium.org/blink/trunk@163887 bbb929c8-8fbe-4397-9dbb-9b2b20218538