Have you tried it out?? Seems interesting....you click the tool icon, then select "New icognito window"...

You've gone incognito. Pages you view in this window won't appear in your browser history or search history, and they won't leave other traces, like cookies, on your computer after you close allopen incognito windows. Any files you download or bookmarks you create will be preserved, however.

Going incognito doesn't affect the behavior of other people, servers, or software. Be wary of:
  • Websites that collect or share information about you
  • Internet service providers or employers that track the pages you visit
  • Malicious software that tracks your keystrokes in exchange for free smileys
  • Surveillance by secret agents
  • People standing behind you

Learn more about incognito browsing.
Because Google Chrome does not control how extensions handle your personal data, all extensions have been disabled for incognito windows. You can reenable them individually in the extensions manager.