MD History: Remove isFirstItem property from history-item

chrome/browser/resources/md_history/app.crisper.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.
 function PromiseResolver() {
   this.resolve_;
   this.reject_;
   this.promise_ = new Promise(function(resolve, reject) {
     this.resolve_ = resolve;
     this.reject_ = reject;
   }.bind(this));
@@ skipping 6693 matching lines @@
         type: Object,
         observer: 'showIcon_'
       },
       searchTerm: {
         type: String
       },
       selected: {
         type: Boolean,
         reflectToAttribute: true
       },
-      isFirstItem: {
-        type: Boolean,
-        reflectToAttribute: true
-      },
       isCardStart: {
         type: Boolean,
         reflectToAttribute: true
       },
       isCardEnd: {
         type: Boolean,
         reflectToAttribute: true
       },
       embedded: {
         type: Boolean,
@@ skipping 1323 matching lines @@
     return md_history.HistoryItem.needsTimeGap(this.historyData_, index, this.searchedTerm);
   },
   isCardStart_: function(item, i, length) {
     if (length == 0 || i > length - 1) return false;
     return i == 0 || this.historyData_[i].dateRelativeDay != this.historyData_[i - 1].dateRelativeDay;
   },
   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;
   },
-  isFirstItem_: function(index) {
-    return index == 0;
-  },
   notifyListScroll_: function() {
     this.fire('history-list-scrolled');
   },
   pathForItem_: function(index) {
     return 'historyData_.' + index;
   }
 });
 
 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
@@ skipping 623 matching lines @@
 
        case HistoryRange.MONTH:
         histogramValue = HistoryPageViewHistogram.GROUPED_MONTH;
         break;
       }
       break;
     }
     md_history.BrowserService.getInstance().recordHistogram('History.HistoryPageView', histogramValue, HistoryPageViewHistogram.END);
   }
 });