Changes to run Swarm from the Editor and to suppress warnings.

samples/swarm/App.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 /**
  * The base class that should be extended by all HTML applications.
  *
  * It should both be easy to use for users coming over from JavaScript, but
  * also offer a clear notion of OO encapsulation.
  *
@@ skipping 83 matching lines @@
   /**
     * Gets the server URL. This is needed when we are loaded from a packaged
     * Chrome app.
     */
   static String serverUrl(String url) {
     if (isPackaged) {
       // TODO(jmesserly): Several problems with this:
       //   * How do we authenticate against the server?
       //   * How do we talk to a server other than thump?
       assert(url.startsWith('/'));
-      return 'http://thump.googleplex.com' + url;
+      return 'http://thump.googleplex.com$url';
     } else {
       return url;
     }
   }
 }