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

chrome/test/data/webui/md_history/history_synced_tabs_test.js

Index: chrome/test/data/webui/md_history/history_synced_tabs_test.js
diff --git a/chrome/test/data/webui/md_history/history_synced_tabs_test.js b/chrome/test/data/webui/md_history/history_synced_tabs_test.js
index dc2f6d182c365d3419a50fbf40cd35f1ebea970e..07e0c8d3d77f3a7efc8bb33afd8802675a70f4d2 100644
--- a/chrome/test/data/webui/md_history/history_synced_tabs_test.js
+++ b/chrome/test/data/webui/md_history/history_synced_tabs_test.js
@@ -32,8 +32,8 @@ cr.define('md_history.history_synced_tabs_test', function() {
       var sidebarElement;
 
       suiteSetup(function() {
-        element = $('history-synced-device-manager');
-        sidebarElement = $('history-side-bar');
+        element = $('history-app').$['history-list'];
+        sidebarElement = $('history-app').$['history-side-bar'];
       });
 
       test('sidebar displayed', function() {