After a supervised user has been imported, close overlays.

chrome/browser/resources/options/options_page.js

Index: chrome/browser/resources/options/options_page.js
diff --git a/chrome/browser/resources/options/options_page.js b/chrome/browser/resources/options/options_page.js
index 303d16781074416a7f47c98f7ffc94e20870324d..01c772ffaa581a6490cf1e777009c221a551815c 100644
--- a/chrome/browser/resources/options/options_page.js
+++ b/chrome/browser/resources/options/options_page.js
@@ -347,6 +347,15 @@ cr.define('options', function() {
   };
 
   /**
+   * 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() {