Remove references to IsNewAvatarMenu since the flag was removed.

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 77 matching lines @@
       };
 
       $('create-profile-supervised-signed-in-learn-more-link').onclick =
           function(event) {
         PageManager.showPageByName('supervisedUserLearnMore');
         return false;
       };
 
       $('create-profile-supervised-sign-in-link').onclick =
           function(event) {
-        // Without the new avatar menu, the signin process will open an overlay
-        // to configure sync, which would replace this overlay. It's smoother to
-        // close this one now.
-        // With the new avatar menu enabled, a sign-in flow in the avatar menu
-        // is triggered instead, which does not open any overlays, so there's no
-        // need to close this one.
-        if (!loadTimeData.getBoolean('newAvatarMenuEnabled')) {
-          // TODO(pamg): Move the sync-setup overlay to a higher layer so this
-          // one can stay open under it, after making sure that doesn't break
-          // anything else.
-          PageManager.closeOverlay();
-        }
         SyncSetupOverlay.startSignIn();
       };
 
       $('create-profile-supervised-sign-in-again-link').onclick =
           function(event) {
-        if (!loadTimeData.getBoolean('newAvatarMenuEnabled'))
-          PageManager.closeOverlay();
         SyncSetupOverlay.showSetupUI();
       };
 
       $('import-existing-supervised-user-link').onclick = function(event) {
         // Hide the import button to trigger a cursor update. The import button
         // is shown again when the import overlay loads. TODO(akuegel): Remove
         // this temporary fix when crbug/246304 is resolved.
         $('import-existing-supervised-user-link').hidden = true;
         PageManager.showPageByName('supervisedUserImport');
       };
@@ skipping 748 matching lines @@
     'updateSignedInStatus',
     'updateSupervisedUsersAllowed',
   ]);
 
   // Export
   return {
     ManageProfileOverlay: ManageProfileOverlay,
     CreateProfileOverlay: CreateProfileOverlay,
   };
 });