Print Preview: Mac: Do not blur focused item while opening the hamburger menu.

chrome/browser/resources/print_preview/search/destination_list.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('print_preview', function() {
   'use strict';
 
   /**
    * Component that displays a list of destinations with a heading, action link,
    * and "Show All..." button. An event is dispatched when the action link is
@@ skipping 318 matching lines @@
      */
     updateListItem_: function(listEl, listItem, focusedEl, destination) {
       listItem.update(destination, this.query_);
 
       var itemEl = listItem.getElement();
       // Preserve focused inner element, if there's one.
       var focusedInnerEl = focusedEl ? itemEl.querySelector(':focus') : null;
       if (focusedEl)
         itemEl.classList.add('moving');
       // Move it to the end of the list.
-      listEl.appendChild(itemEl);
+      if (listEl.lastChild != itemEl)

[dpapad, 2017/05/23 01:02:06]

Without a regression test, and without any comment explaining why this check is
necessary, this check is not obvious and it is likely that someone might try to
remove it in the future, and silently regress what this CL is fixing.

Can we at least add a comment?

[tkent, 2017/05/23 03:54:53]

I found why :focus didn't work, and Patch Set 2 removed this hacky |if|.

+        listEl.appendChild(itemEl);
       // Restore focus.
       if (focusedEl) {
         if (focusedEl == itemEl || focusedEl == focusedInnerEl)
           focusedEl.focus();
         itemEl.classList.remove('moving');
       }
     },
 
     /**
      * @param {Element} listEl List element.
@@ skipping 17 matching lines @@
       cr.dispatchSimpleEvent(this,
                              DestinationList.EventType.ACTION_LINK_ACTIVATED);
     }
   };
 
   // Export
   return {
     DestinationList: DestinationList
   };
 });