Send console messages through interaction manager.

dart/site/try/src/ui.dart

Index: dart/site/try/src/ui.dart
diff --git a/dart/site/try/src/ui.dart b/dart/site/try/src/ui.dart
index 0c7d24dc4ab73b7efb319f850962e5fca71b6274..e678f389035e7a431b8162c86d0bdcc6ac91ac58 100644
--- a/dart/site/try/src/ui.dart
+++ b/dart/site/try/src/ui.dart
@@ -92,6 +92,7 @@ void onCodeChange(Event event) {
   Function action = codeCallbacks[id];
   if (action != null) action(event);
   outputFrame.style.display = 'none';
+  outputDiv.nodes.clear();
 }
 
 buildUI() {
@@ -198,7 +199,7 @@ buildUI() {
   var settingsElement = document.getElementById('settings');
   settingsElement.onClick.listen(openSettings);
 
-  window.onMessage.listen(interaction.onMessage);
+  window.onMessage.listen(interaction.onWindowMessage);
 
   observer = new MutationObserver(interaction.onMutation)
       ..observe(