[MD History] Add URL parameter for search.

chrome/browser/resources/md_history/side_bar.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: 'history-side-bar',
 
   properties: {
     selectedPage: {
       type: String,
       notify: true
     },
+
+    route: Object,
   },
 
   toggle: function() {
     this.$.drawer.toggle();
   },
 
   /** @private */
   onDrawerFocus_: function() {
     // The desired behavior is for the app-drawer to focus the currently
     // selected menu item on opening. However, it will always focus the first
@@ skipping 10 matching lines @@
 
   /**
    * Relocates the user to the clear browsing data section of the settings page.
    * @param {Event} e
    * @private
    */
   onClearBrowsingDataTap_: function(e) {
     md_history.BrowserService.getInstance().openClearBrowsingData();
     e.preventDefault();
   },
+
+  /**
+   * @param {Object} route
+   * @private
+   */
+  getQueryString_: function(route) {
+    return window.location.search;
+  }
 });