MD User Manager: Display error message when all profiles are locked.

chrome/browser/resources/md_user_manager/control_bar.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview 'control-bar' is the horizontal bar at the bottom of the user
  * manager screen.
  */
  Polymer({
   is: 'control-bar',
 
+  behaviors: [
+    I18nBehavior,
+  ],
+
   properties: {
     /**
      * True if 'Browse as Guest' button is displayed.
      * @type {boolean}
      */
     showGuest: {
       type: Boolean,
       value: false
     },
 
@@ skipping 14 matching lines @@
   created: function() {
     this.browserProxy_ = signin.ProfileBrowserProxyImpl.getInstance();
   },
 
   /**
    * Handler for 'Browse as Guest' button click event.
    * @param {!Event} event
    * @private
    */
   onLaunchGuestTap_: function(event) {
-    this.browserProxy_.launchGuestUser();
+    this.browserProxy_.areAllProfilesLocked().then(
+        function(allProfilesLocked) {
+          if (!allProfilesLocked) {
+            this.browserProxy_.launchGuestUser();
+          } else {
+            cr.webUIListenerCallback(

[dpapad, 2016/05/31 21:05:51]

The original intent of cr.webUIListenerCallback is to send events from C++ to
JS. Can you open the dialog more explicitly here instead of using a "webUI
event" from JS to JS? How about

UserManager.showErrorDialog(this.i18n('BrowseAsGuestAllProfilesLockedError'));

[Moe, 2016/05/31 22:14:05]

b/c user_manager.js includes a bunch of legacy js code we don't closure compile
it. Closure compiler won't be happy with this call. I'll go with
document.querySelector()

+                'show-error-dialog',
+                this.i18n('BrowseAsGuestAllProfilesLockedError'));
+          }
+        }.bind(this));
   },
 
   /**
    * Handler for 'Add Person' button click event.
    * @param {!Event} event
    * @private
    */
   onAddUserTap_: function(event) {
-    // Event is caught by user-manager-pages.
-    this.fire('change-page', {page: 'create-user-page'});
+    this.browserProxy_.areAllProfilesLocked().then(
+        function(allProfilesLocked) {
+          if (!allProfilesLocked) {
+            // Event is caught by user-manager-pages.
+            this.fire('change-page', {page: 'create-user-page'});
+          } else {
+            cr.webUIListenerCallback(

[dpapad, 2016/05/31 21:05:51]

Same here.

[Moe, 2016/05/31 22:14:05]

Done.

+                'show-error-dialog',
+                this.i18n('AddProfileAllProfilesLockedError'));
+          }
+        }.bind(this));
   }
 });