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

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

Index: chrome/test/data/webui/md_history/md_history_browsertest.js
diff --git a/chrome/test/data/webui/md_history/md_history_browsertest.js b/chrome/test/data/webui/md_history/md_history_browsertest.js
index ee4614022f86e048a937e64502cdf62f10f4612e..e8b5cb130c1619e556849c496d95f21902f436d5 100644
--- a/chrome/test/data/webui/md_history/md_history_browsertest.js
+++ b/chrome/test/data/webui/md_history/md_history_browsertest.js
@@ -37,7 +37,8 @@ MaterialHistoryBrowserTest.prototype = {
     'history_routing_test.js',
     'history_supervised_user_test.js',
     'history_synced_tabs_test.js',
-    'history_toolbar_test.js'
+    'history_toolbar_test.js',
+    'lazy_render_test.js'
   ]),
 
   /** @override */
@@ -88,6 +89,11 @@ TEST_F('MaterialHistoryBrowserTest', 'HistoryOverflowMenuTest', function() {
   mocha.run();
 });
 
+TEST_F('MaterialHistoryBrowserTest', 'LazyRenderTest', function() {
+  md_history.lazy_render_test.registerTests();
+  mocha.run();
+});
+
 TEST_F('MaterialHistoryBrowserTest', 'RoutingTest', function() {
   md_history.history_routing_test.registerTests();
   mocha.run();