MD History: Remove isFirstItem property from history-item

chrome/browser/resources/md_history/history_list.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.
 
 Polymer({
   is: 'history-list',
 
   behaviors: [HistoryListBehavior],
 
   properties: {
@@ skipping 135 matching lines @@
    */
   isCardEnd_: function(item, i, length) {
     if (length == 0 || i > length - 1)
       return false;
     return i == length - 1 ||
         this.historyData_[i].dateRelativeDay !=
         this.historyData_[i + 1].dateRelativeDay;
   },
 
   /**
-   * @param {number} index
-   * @return {boolean}
-   * @private
-   */
-  isFirstItem_: function(index) {
-    return index == 0;
-  },
-
-  /**
    * @private
    */
   notifyListScroll_: function() {
     this.fire('history-list-scrolled');
   },
 
   /**
    * @param {number} index
    * @return {string}
    * @private
    */
   pathForItem_: function(index) {
     return 'historyData_.' + index;
   },
 });