After a supervised user has been imported, close overlays.

chrome/browser/resources/options/options_page.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() {
   /** @const */ var FocusOutlineManager = cr.ui.FocusOutlineManager;
 
   /////////////////////////////////////////////////////////////////////////////
   // OptionsPage class:
 
@@ skipping 329 matching lines @@
 
     overlay.visible = false;
 
     if (overlay.didClosePage) overlay.didClosePage();
     this.updateHistoryState_(false, {ignoreHash: true});
 
     this.restoreLastFocusedElement_();
   };
 
   /**
+   * Closes all overlays and updates the history after each closed overlay.
+   */
+  OptionsPage.closeAllOverlays = function() {
+    while (this.isOverlayVisible_()) {
+      this.closeOverlay();
+    }
+  };
+
+  /**
    * Cancels (closes) the overlay, due to the user pressing <Esc>.
    */
   OptionsPage.cancelOverlay = function() {
     // Blur the active element to ensure any changed pref value is saved.
     document.activeElement.blur();
     var overlay = this.getVisibleOverlay_();
     // Let the overlay handle the <Esc> if it wants to.
     if (overlay.handleCancel) {
       overlay.handleCancel();
       this.restoreLastFocusedElement_();
@@ skipping 642 matching lines @@
     canShowPage: function() {
       return true;
     },
   };
 
   // Export
   return {
     OptionsPage: OptionsPage
   };
 });