Add a lock to the managed user settings page and require authentication for unlocking.

chrome/browser/resources/options/managed_user_set_passphrase.js

Index: chrome/browser/resources/options/managed_user_set_passphrase.js
diff --git a/chrome/browser/resources/options/managed_user_set_passphrase.js b/chrome/browser/resources/options/managed_user_set_passphrase.js
index 9db2e8db90c05d9281dec0d3c9562d6ceaa47732..fe7da9fb641c34e04739113953808272e5d00ed4 100644
--- a/chrome/browser/resources/options/managed_user_set_passphrase.js
+++ b/chrome/browser/resources/options/managed_user_set_passphrase.js
@@ -48,6 +48,11 @@ cr.define('options', function() {
           !$('passphrase-confirm').validity.valid ||
           !$('managed-user-passphrase').validity.valid;
     },
+    /** @override */

[James Hawkins, 2013/02/20 17:24:56]

nit: Blank line above this.

[Adrian Kuegel, 2013/02/20 18:05:02]

Done.

+    canShowPage: function() {
+      return ManagedUserSettings.getInstance().authenticationState ==
+          options.ManagedUserAuthentication.AUTHENTICATED;
+    },
   };
 
   // This is a class used for browsertests.