In the beta release in November, Google added the ability to switch between users in Chrome browser. This feature is now live in today’s new stable release of Chrome.
Now you can go to the wrench icon > Options (or Preferences) > Personal Stuff > Add new user to add new user accounts. You can then switch among these accounts. This is a very handy feature that allows all users of a shared computer to access to their own settings, bookmarks and apps easily. A possible use is a computer shared by different family members.
Watch this video to learn more:
source Official Google Chrome Blog