[MD History] Factor out a common HistoryListBehavior.

chrome/browser/resources/md_history/grouped_list.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.
 
 /**
  * @typedef {{domain: string,
  *            visits: !Array<HistoryEntry>,
  *            rendered: boolean,
  *            expanded: boolean}}
  */
 var HistoryDomain;
 
 /**
  * @typedef {{title: string,
  *            domains: !Array<HistoryDomain>}}
  */
 var HistoryGroup;
 
 // TODO(calamity): Support selection by refactoring selection out of
 // history-list and into history-app.

[tsergeant, 2016/08/05 01:39:09]

This can be deleted now 🙌

[calamity, 2016/08/09 02:56:00]

Done.

 Polymer({
   is: 'history-grouped-list',
 
+  behaviors: [HistoryListBehavior],
+
   properties: {
     // An array of history entries in reverse chronological order.
     historyData: {
       type: Array,
     },
 
     /**
      * @type {Array<HistoryGroup>}
      */
     groupedHistoryData_: {
@@ skipping 115 matching lines @@
    * @private
    */
   needsTimeGap_: function(groupIndex, domainIndex, itemIndex) {
     var visits =
         this.groupedHistoryData_[groupIndex].domains[domainIndex].visits;
 
     return md_history.HistoryItem.needsTimeGap(
         visits, itemIndex, this.searchedTerm);
   },
 
-  hasResults_: function(historyDataLength) {
-    return historyDataLength > 0;
+  /**
+   * @param {number} groupIndex
+   * @param {number} domainIndex
+   * @param {number} itemIndex
+   * @return {string}
+   * @private
+   */
+  pathForItem_: function(groupIndex, domainIndex, itemIndex) {
+    return [
+      'groupedHistoryData_', groupIndex, 'domains', domainIndex, 'visits',
+      itemIndex
+    ].join('.');
   },
 
+  /**
+   * @param {HistoryDomain} domain
+   * @return {string}
+   * @private
+   */
   getWebsiteIconStyle_: function(domain) {
     return 'background-image: ' +
         cr.icon.getFaviconImageSet(domain.visits[0].url);
   },
 
+  /**
+   * @param {boolean} expanded
+   * @return {string}
+   * @private
+   */
   getDropdownIcon_: function(expanded) {
     return expanded ? 'cr:expand-less' : 'cr:expand-more';
   },
-
-  noResultsMessage_: function(searchedTerm) {
-    var messageId = searchedTerm !== '' ? 'noSearchResults' : 'noResults';
-    return loadTimeData.getString(messageId);
-  },
 });