[MD History] Refactor history.html into a history-app element.

chrome/test/data/webui/md_history/history_item_test.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.
 
 cr.define('md_history.history_item_test', function() {
   function registerTests() {
     suite('history-item', function() {
       var element;
       var TEST_HISTORY_RESULTS;
       var SEARCH_HISTORY_RESULTS;
 
       suiteSetup(function() {
-        element = $('history-list');
+        element = $('history-app').$['history-list'];
         TEST_HISTORY_RESULTS = [
           createHistoryEntry('2016-03-16 10:00', 'http://www.google.com'),
           createHistoryEntry('2016-03-16 9:00', 'http://www.example.com'),
           createHistoryEntry('2016-03-16 7:01', 'http://www.badssl.com'),
           createHistoryEntry('2016-03-16 7:00', 'http://www.website.com'),
           createHistoryEntry('2016-03-16 4:00', 'http://www.website.com'),
           createHistoryEntry('2016-03-15 11:00', 'http://www.example.com'),
         ];
 
         SEARCH_HISTORY_RESULTS = [
@@ skipping 62 matching lines @@
 
       teardown(function() {
         element.historyData = [];
       });
     });
   }
   return {
     registerTests: registerTests
   };
 });