[MD History] Implement grouped history UI.

chrome/browser/resources/md_history/history_toolbar.js

 // Copyright 2015 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.
 
 /**
  * @constructor
  * @implements {SearchFieldDelegate}
  * @param {!HistoryToolbarElement} toolbar This history-toolbar.
  */
 function ToolbarSearchFieldDelegate(toolbar) {
@@ skipping 41 matching lines @@
     // Whether domain-grouped history is enabled.
     isGroupedMode: {
       type: Boolean,
       reflectToAttribute: true,
     },
 
     // The period to search over. Matches BrowsingHistoryHandler::Range.
     groupedRange: {
       type: Number,
       value: 0,
-      reflectToAttribute: true
+      reflectToAttribute: true,
+      notify: true
     },
 
     // The start time of the query range.
     queryStartTime: String,
 
     // The end time of the query range.
     queryEndTime: String,
   },
 
   /**
@@ skipping 54 matching lines @@
   numberOfItemsSelected_: function(count) {
     return count > 0 ? loadTimeData.getStringF('itemsSelected', count) : '';
   },
 
   getHistoryInterval_: function(queryStartTime, queryEndTime) {
     // TODO(calamity): Fix the format of these dates.
     return loadTimeData.getStringF(
       'historyInterval', queryStartTime, queryEndTime);
   }
 });