Settings to control Add Person and Browse as Guest.

chrome/browser/resources/user_manager/user_manager.js

Index: chrome/browser/resources/user_manager/user_manager.js
diff --git a/chrome/browser/resources/user_manager/user_manager.js b/chrome/browser/resources/user_manager/user_manager.js
index 84fab310838f06db9530d2f80d89a7b65d3e1eb0..14d910d074a3a0632586e9b9f65e6880ea06f2bc 100644
--- a/chrome/browser/resources/user_manager/user_manager.js
+++ b/chrome/browser/resources/user_manager/user_manager.js
@@ -34,15 +34,16 @@ cr.define('cr.ui', function() {
    * Shows the given screen.
    * @param {Object} screen Screen params dict, e.g. {id: screenId, data: data}

[Marc Treib, 2014/09/01 08:49:53]

nit: The comment is inaccurate/out-of-date (not your fault of course, but would
still be nice to fix)

[Mike Lerman, 2014/09/02 16:58:29]

Done.

    */
-  Oobe.showUserManagerScreen = function(showGuest) {
+  Oobe.showUserManagerScreen = function(showGuest, showAddPerson) {
     Oobe.getInstance().showScreen({id: 'account-picker',
                                    data: {disableAddUser: false}});
     // The ChromeOS account-picker will hide the AddUser button if a user is
     // logged in and the screen is "locked", so we must re-enabled it
     $('add-user-header-bar-item').hidden = false;
 
-    // Hide the Guest Mode option if the user is not permitted to select it.
+    // Hide control options if the user does not have the right permissions.
     $('guest-user-button').hidden = !showGuest;
+    $('add-user-button').hidden = !showAddPerson;
     $('login-header-bar').hidden = false;
 
     // Disable the context menu, as the Print/Inspect element items don't