Noop scrollFocusedPodIntoView on Windows, Linux and Mac

ui/login/account_picker/user_pod_row.js

 // Copyright 2014 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.
 
 /**
  * @fileoverview User pod row implementation.
  */
 
 cr.define('login', function() {
   /**
@@ skipping 2303 matching lines @@
     /**
      * Scrolls focused user pod into view.
      */
     scrollFocusedPodIntoView: function() {
       var pod = this.focusedPod_;
       if (!pod)
         return;
 
       // First check whether focused pod is already fully visible.
       var visibleArea = $('scroll-container');
+      // Visible area may not defined at user manager screen on all platforms.
+      // Windows, Mac and Linux do not have visible area.
+      if (!visibleArea)
+        return;
       var scrollTop = visibleArea.scrollTop;
       var clientHeight = visibleArea.clientHeight;
       var podTop = $('oobe').offsetTop + pod.offsetTop;
       var padding = USER_POD_KEYBOARD_MIN_PADDING;
       if (podTop + pod.height + padding <= scrollTop + clientHeight &&
           podTop - padding >= scrollTop) {
         return;
       }
 
       // Scroll so that user pod is as centered as possible.
@@ skipping 814 matching lines @@
        if (pod && pod.multiProfilesPolicyApplied) {
          pod.userTypeBubbleElement.classList.remove('bubble-shown');
        }
      }
   };
 
   return {
     PodRow: PodRow
   };
 });