Added TodoMVC startup benchmarks.

samples/third_party/todomvc_performance/web/performance.dart

Index: samples/third_party/todomvc_performance/web/performance.dart
diff --git a/samples/third_party/todomvc_performance/web/performance.dart b/samples/third_party/todomvc_performance/web/performance.dart
new file mode 100644
index 0000000000000000000000000000000000000000..94cd17958ece225828d73f207bc725df7d98941e
--- /dev/null
+++ b/samples/third_party/todomvc_performance/web/performance.dart
@@ -0,0 +1,31 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file

[Jennifer Messerly, 2014/03/19 19:27:57]

not a big deal but could be 2014 :)

[Emily Fortuna, 2014/03/24 19:45:56]

Done.

+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library todomvc.test.markdone_test;

[Jennifer Messerly, 2014/03/19 19:27:57]

change library name?

[Emily Fortuna, 2014/03/24 19:45:56]

Done.

+
+import 'dart:async';
+import 'dart:html';
+import 'dart:js' as js;
+import 'package:polymer/polymer.dart';
+import 'package:web_components/polyfill.dart';
+import 'elements/td_model.dart';
+
+/**
+ * This test determines how fast the TodoMVC app has loaded.
+ */
+main() {
+  initPolymer();
+  customElementsReady.then((_) {
+    var endInitTime = new DateTime.now();
+    window.postMessage(endInitTime.millisecondsSinceEpoch, '*');
+  });
+
+  // Failover case; sometimes in the Dartium version, customElementsReady has
+  // already fired before Dart starts to run. allows the test to complete for
+  // that state.
+  Polymer.onReady.then((_) {

[Jennifer Messerly, 2014/03/19 19:27:57]

fyi -- I think this event is always more reliable as far as Polymer.dart
startup.

[Emily Fortuna, 2014/03/24 19:45:56]

Done.

+    var endInitTime = new DateTime.now();
+    window.postMessage(endInitTime.millisecondsSinceEpoch, '*');
+  });
+}