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

samples/swarm/UIState.dart

Index: samples/swarm/UIState.dart
diff --git a/samples/swarm/UIState.dart b/samples/swarm/UIState.dart
index 731615783166c4ac403fb461b36829053af5de05..b5a7c0acb63fee48aa693213e6961e02116d1f41 100644
--- a/samples/swarm/UIState.dart
+++ b/samples/swarm/UIState.dart
@@ -58,7 +58,7 @@ class UIState {
     // TODO(jmesserly): [state] should be an Object, and we should pass it to
     // the state parameter instead of as a #hash URL. Right now we're working
     //  around b/4582542.
-    window.history.pushState(null, document.title, '#' + state);
+    window.history.pushState(null, '${document.title}#$state');
   }
 
   /**