MD History: Add lazy-render element for simple lazy initialization.

chrome/browser/resources/md_history/constants.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.
 
 // Globals:
 /** @const */ var RESULTS_PER_PAGE = 150;
 
 /**
  * Amount of time between pageviews that we consider a 'break' in browsing,
  * measured in milliseconds.
@@ skipping 10 matching lines @@
 var TITLE_MAX_LENGTH = 300;
 
 /**
  * @enum {number}
  */
 var HistoryRange = {
   ALL_TIME: 0,
   WEEK: 1,
   MONTH: 2
 };
-
-// Types:
-/**
- * @typedef {{groupedOffset: number,
- *            incremental: boolean,
- *            querying: boolean,
- *            range: HistoryRange,
- *            searchTerm: string}}
- */
-var QueryState;
-
-/**
- * @typedef {{info: ?HistoryQuery,
- *            results: ?Array<!HistoryEntry>,
- *            sessionList: ?Array<!ForeignSession>}}
- */
-var QueryResult;
-
-/** @constructor
- *  @extends {MouseEvent} */
-var DomRepeatClickEvent = function() {
-  this.model = null;
-};