Added TodoMVC startup benchmarks.

samples/third_party/todomvc_performance/web/lib-elements/simple_router.dart

 // Copyright 2013 The Polymer Authors. 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.web.lib_elements.simple_router;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:polymer/polymer.dart';
 
 // A very simple router for TodoMVC. Real app should use package:route, but it
@@ skipping 19 matching lines @@
   }
 
   leftView() {
     _sub.cancel();
   }
 
   routeChanged() {
     fire('route', detail: route);
   }
 }