Account Picker: fix window resize.

ui/login/account_picker/screen_account_picker.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 Account picker screen implementation.
  */
 
 login.createScreen('AccountPickerScreen', 'account-picker', function() {
   /**
@@ skipping 207 matching lines @@
             cr.ui.LoginUITools.getMaxHeightBeforeShelfOverlapping(bubbleAnchor)
           - bubbleAnchor.offsetHeight - BUBBLE_POD_OFFSET;
         var maxWidth = cr.ui.LoginUITools.getMaxWidthToFit(bubbleAnchor)
           - bubbleAnchor.offsetWidth - BUBBLE_POD_OFFSET;
 
         // Change bubble visibility temporary to calculate height.
         var bubbleVisibility = bubble.style.visibility;
         bubble.style.visibility = 'hidden';
         bubble.hidden = false;
         // Now we need the bubble to have the new content before calculating
-        // size.
-        bubble.replaceContent(error);
+        // size. Undefined |error| == reuse old content.
+        if (error !== undefined)
+          bubble.replaceContent(error);
+
         // Get bubble size.
         var bubbleOffsetHeight = parseInt(bubble.offsetHeight);
         var bubbleOffsetWidth = parseInt(bubble.offsetWidth);
         // Restore attributes.
         bubble.style.visibility = bubbleVisibility;
         bubble.hidden = true;
 
         if (attachment == cr.ui.Bubble.Attachment.BOTTOM) {
           // Move error bubble if it overlaps the shelf.
           if (maxHeight < bubbleOffsetHeight)
@@ skipping 225 matching lines @@
      * @param {string} userID The user ID of the public session
      * @param {string} locale The locale to which this list of keyboard layouts
      *     applies
      * @param {!Object} list List of available keyboard layouts
      */
     setPublicSessionKeyboardLayouts: function(userID, locale, list) {
       $('pod-row').setPublicSessionKeyboardLayouts(userID, locale, list);
     }
   };
 });