Store encrypted hash of user's password for future off-line auth.

This is just the first step towards the off-line authentication required for being able to reconnect a profile that has signed out.  The push towards offline support in Apps means that we have to be able to authenticate even when no Internet connection is available.

There is currently no code that actually calls the Validate function.

Requires --new-profile-management flag.

BUG=239800

Review URL: https://codereview.chromium.org/23402004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230777 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230777
Add myself to authors

NOTRY=true

Review URL: https://codereview.chromium.org/37053005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230778 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230778