[MD History] Implement grouped history UI.

chrome/test/data/webui/md_history/test_util.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.
 
 /*
  * Waits for queued up tasks to finish before proceeding. Inspired by:
  * https://github.com/Polymer/web-component-tester/blob/master/browser/environment/helpers.js#L97
  */
 function flush(callback) {
   Polymer.dom.flush();
@@ skipping 37 matching lines @@
  * @return {!HistoryEntry} An object representing a history entry.
  */
 function createSearchEntry(timestamp, urlStr) {
   var entry = createHistoryEntry(timestamp, urlStr);
   entry.dateShort = entry.dateRelativeDay;
   entry.dateTimeOfDay = '';
   entry.dateRelativeDay = '';
 
   return entry;
 }
+
+/**
+ * Create a simple HistoryInfo.
+ * @param {?string} searchTerm The search term that the info has. Will be empty
+ *     string if not specified.
+ * @return {!HistoryInfo}
+ */
+function createHistoryInfo(searchTerm) {
+  return {
+          finished: true,

[tsergeant, 2016/05/25 05:06:56]

Nit: normal formatting is probably

return {
  finished: true
  ...
};

[calamity, 2016/05/25 05:51:41]

Done.

+          hasSyncedResults: false,
+          queryEndTime: 'Monday',
+          queryStartTime: 'Tuesday',
+          term: searchTerm || ''
+        };
+}