[MD History] Fix toolbar dates in grouped mode.

chrome/browser/resources/md_history/history_toolbar.js

Index: chrome/browser/resources/md_history/history_toolbar.js
diff --git a/chrome/browser/resources/md_history/history_toolbar.js b/chrome/browser/resources/md_history/history_toolbar.js
index fbe0359cf4e4a7509cf13028eea962723dd3b986..d0fa68ef4d251fbcd07b4d772bee9be6334cf4a2 100644
--- a/chrome/browser/resources/md_history/history_toolbar.js
+++ b/chrome/browser/resources/md_history/history_toolbar.js
@@ -51,15 +51,11 @@ Polymer({
       notify: true,
     },
 
-    querying: Boolean,
-
     hasMoreResults: Boolean,
 
-    // The start time of the query range.
-    queryStartTime: String,
+    querying: Boolean,
 
-    // The end time of the query range.
-    queryEndTime: String,
+    queryInfo: Object,

[calamity, 2016/12/15 02:17:52]

Just FYI, I considered adding a couple more String properties here but if the
same values ever came back when the range changed, (e.g switching from Week to
Month on the 7th), then the computed value wouldn't get updated. So....
queryInfo it is.

 
     // Whether to show the menu promo (a tooltip that points at the menu button
     // in narrow mode).
@@ -131,10 +127,15 @@ Polymer({
   },
 
   /** @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 loadTimeData.getStringF(
+        'historyInterval', info.queryStartTimeShort, info.queryEndTimeShort);
+    }
+
+    if (this.groupedRange == HistoryRange.MONTH)
+      return info.queryStartMonth;
   },
 
   /** @private */