chrome://settings should allow duplicate profile names.

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 420 matching lines @@
     /**
      * Called to update the state of the ok button depending if the name is
      * already used or not.
      * @param {string} mode A label that specifies the type of dialog box which
      *     is currently being viewed (i.e. 'create' or 'manage').
      * @private
      */
     updateOkButton_: function(mode) {
       var oldName = this.profileInfo_.name;
       var newName = $(mode + '-profile-name').value;
-      var nameIsDuplicate = this.existingProfileNames_[newName] != undefined;
-      if (mode == 'manage' && oldName == newName)
-        nameIsDuplicate = false;
-      if (nameIsDuplicate) {
-        var errorHtml =
-            loadTimeData.getString('manageProfilesDuplicateNameError');
-        this.showErrorBubble_(errorHtml, mode, true);
-      } else {
-        this.hideErrorBubble_(mode);
+      this.hideErrorBubble_(mode);
 
-        var nameIsValid = $(mode + '-profile-name').validity.valid;
-        $(mode + '-profile-ok').disabled = !nameIsValid;
-      }
+      var nameIsValid = $(mode + '-profile-name').validity.valid;
+      $(mode + '-profile-ok').disabled = !nameIsValid;
     },
 
     /**
      * Called when the user clicks "OK" or hits enter. Saves the newly changed
      * profile info.
      * @private
      */
     submitManageChanges_: function() {
       var name = $('manage-profile-name').value;
       var iconURL = $('manage-profile-icon-grid').selectedItem;
@@ skipping 423 matching lines @@
     'updateSignedInStatus',
     'updateSupervisedUsersAllowed',
   ]);
 
   // Export
   return {
     ManageProfileOverlay: ManageProfileOverlay,
     CreateProfileOverlay: CreateProfileOverlay,
   };
 });