[MD Bookmarks] Add search.

chrome/browser/resources/md_bookmarks/folder_node.js

 // Copyright 2016 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.
 
 Polymer({
   is: 'bookmarks-folder-node',
 
   properties: {
     /** @type {BookmarkTreeNode} */
     item: Object,
 
     isSelected: {
       type: Boolean,
       value: false,
       reflectToAttribute: true,
     },
+
+    sidebarActive: {

[tsergeant, 2017/01/06 02:43:54]

To avoid passing this all the way down the tree, is it possible to actually have
no node selected in the tree?

You'd just need to make sure the page recovers correctly when the search is
cleared.

This is kind of similar to what the old page does, and it goes back to selecting
'Bookmarks bar' when a search is cleared.

[angelayang, 2017/01/12 05:04:32]

Done.

+      type: Boolean,
+      value: true,
+      reflectToAttribute: true,
+    },
   },
 
   /**
    * @private
    * @return {string}
    */
   getFolderIcon_: function() {
-    return this.isSelected ? 'bookmarks:folder-open' : 'bookmarks:folder';
+    return this.isSelected && this.sidebarActive ? 'bookmarks:folder-open' :
+                                                   'bookmarks:folder';
   },
 
   /**
    * @private
    * @return {string}
    */
   getArrowIcon_: function() {
     return this.item.isOpen ? 'bookmarks:arrow-drop-up' :
                               'bookmarks:arrow-drop-down';
   },
@@ skipping 19 matching lines @@
    * @return {boolean}
    */
   hasChildFolder_: function() {
     for (var i = 0; i < this.item.children.length; i++) {
       if (!this.item.children[i].url)
         return true;
     }
     return false;
   },
 });