[MD Bookmarks] Modify search to retain the previously selected folder.

chrome/browser/resources/md_bookmarks/item.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-item',
 
   properties: {
     /** @type {BookmarkTreeNode} */
     item: {
@@ skipping 45 matching lines @@
       range: e.shiftKey,
       add: e.ctrlKey,
     });
   },
 
   /**
    * @param {Event} e
    * @private
    */
   onDblClick_: function(e) {
-    if (!this.item.url)
-      this.fire('selected-folder-changed', this.item.id);
-    else
+    if (!this.item.url) {
+      this.fire('selected-folder-changed', {
+        id: this.item.id,
+        clearSearch: true,
+      });
+    } else {
       chrome.tabs.create({url: this.item.url});
+    }
   },
 
   /**
    * @param {string} url
    * @private
    */
   updateFavicon_: function(url) {
     this.$.icon.style.backgroundImage = cr.icon.getFavicon(url);
   },
 });