[MD History] Fix toolbar dates in grouped mode.

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.
 
 Polymer({
   is: 'history-toolbar',
   properties: {
     // Number of history items currently selected.
     // TODO(calamity): bind this to
     // listContainer.selectedItem.selectedPaths.length.
@@ skipping 42 matching lines @@
       type: Number,
       reflectToAttribute: true,
       notify: true,
     },
 
     groupedOffset: {
       type: Number,
       notify: true,
     },
 
+    hasMoreResults: Boolean,
+
     querying: Boolean,
 
-    hasMoreResults: Boolean,
-
-    // The start time of the query range.
-    queryStartTime: String,
-
-    // The end time of the query range.
-    queryEndTime: String,
+    queryInfo: Object,
 
     // Whether to show the menu promo (a tooltip that points at the menu button
     // in narrow mode).
     showMenuPromo: Boolean,
 
     showSyncNotice: Boolean,
   },
 
   /** @return {CrToolbarSearchFieldElement} */
   get searchField() {
@@ skipping 61 matching lines @@
   deletingAllowed_: function() {
     return loadTimeData.getBoolean('allowDeletingHistory');
   },
 
   /** @private */
   numberOfItemsSelected_: function(count) {
     return count > 0 ? loadTimeData.getStringF('itemsSelected', count) : '';
   },
 
   /** @private */
-  getHistoryInterval_: function(queryStartTime, queryEndTime) {
-    // TODO(calamity): Fix the format of these dates.
-    return loadTimeData.getStringF(
-        'historyInterval', queryStartTime, queryEndTime);
+  getHistoryInterval_: function() {
+    var info = this.queryInfo;
+    if (this.groupedRange == HistoryRange.WEEK)
+      return info.queryInterval;
+
+    if (this.groupedRange == HistoryRange.MONTH)
+      return info.queryStartMonth;
   },
 
   /** @private */
   onTodayTap_: function() {
     if (!this.querying)
       this.groupedOffset = 0;
   },
 
   /** @private */
   onPrevTap_: function() {
     if (!this.querying)
       this.groupedOffset = this.groupedOffset + 1;
   },
 
   /** @private */
   onNextTap_: function() {
     if (!this.querying)
       this.groupedOffset = this.groupedOffset - 1;
   },
 
   /**
    * @private
    * @return {boolean}
    */
   isToday_: function() {
     return this.groupedOffset == 0;
   },
 });