Show warning message when trying to create SU with existing name

chrome/browser/resources/options/manage_profile_overlay.js

 // Copyright (c) 2012 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.
 
 cr.define('options', function() {
   var Page = cr.ui.pageManager.Page;
   var PageManager = cr.ui.pageManager.PageManager;
   var ArrayDataModel = cr.ui.ArrayDataModel;
 
   /**
@@ skipping 361 matching lines @@
      */
     receiveExistingSupervisedUsers_: function(supervisedUsers) {
       $('import-existing-supervised-user-link').hidden =
           supervisedUsers.length === 0;
       if (!$('create-profile-supervised').checked)
         return;
 
       var newName = $('create-profile-name').value;
       var i;
       for (i = 0; i < supervisedUsers.length; ++i) {
-        if (supervisedUsers[i].name == newName &&
-            !supervisedUsers[i].onCurrentDevice) {
-          var errorHtml = loadTimeData.getStringF(
-              'manageProfilesExistingSupervisedUser',
-              HTMLEscape(elide(newName, /* maxLength */ 50)));
-          this.showErrorBubble_(errorHtml, 'create', true);
-
+        if (supervisedUsers[i].name == newName) {
           // Check if another supervised user also exists with that name.
           var nameIsUnique = true;
+          var allOnCurrentDevice = supervisedUsers[i].onCurrentDevice;

[Marc Treib, 2015/12/10 11:36:41]

I think this is worth a comment: You're handling the case when there already are
multiple SUs with that name, which "shouldn't" happen (for small values of
"shouldn't"). Took me a moment to understand this :)

[Pam (message me for reviews), 2015/12/15 14:31:37]

It can happen if the first SU with that name hasn't been imported onto this
device.

That said, we don't want to support two SUs with the same name at all. There
might be some existing duplicates, though, from the time this bug has existed.
So we should disallow creating a new SU with a name that exists for any SU (not
just on this device) -- but still allow importing any SU that the current user
already has, even if it duplicates a name.

[atanasova, 2015/12/15 17:57:36]

I added a comment to explain this case. It can happen if the user has already
created supervised users with the same name. That is why we need to check, in
order to allow import if not all are synced on the device.

           var j;
           for (j = i + 1; j < supervisedUsers.length; ++j) {
             if (supervisedUsers[j].name == newName) {
               nameIsUnique = false;
-              break;
+              allOnCurrentDevice = allOnCurrentDevice &&
+                 supervisedUsers[j].onCurrentDevice;
             }
           }
+
+          var errorHtml = allOnCurrentDevice ?
+              loadTimeData.getStringF(
+                  'managedProfilesExistingLocalSupervisedUser') :
+              loadTimeData.getStringF(
+                  'manageProfilesExistingSupervisedUser',
+                  HTMLEscape(elide(newName, /* maxLength */ 50)));
+          this.showErrorBubble_(errorHtml, 'create', true);
+
           $('supervised-user-import-existing').onclick =
               this.getImportHandler_(supervisedUsers[i], nameIsUnique);
           $('create-profile-ok').disabled = true;
           return;
         }
       }
     },
 
     /**
      * Called in case the request for the list of supervised users fails because
@@ skipping 453 matching lines @@
     'updateSignedInStatus',
     'updateSupervisedUsersAllowed',
   ]);
 
   // Export
   return {
     ManageProfileOverlay: ManageProfileOverlay,
     CreateProfileOverlay: CreateProfileOverlay,
   };
 });