Enable Try Dart to run on IE11.

site/try/src/leap.dart

 // Copyright (c) 2013, 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.
 
 library trydart.main;
 
 import 'dart:html' show
     HttpRequest,
     LinkElement,
     querySelector,
@@ skipping 13 matching lines @@
     EXAMPLE_HELLO;
 
 import 'ui.dart' show
     buildUI,
     interaction,
     observer;
 
 import 'user_option.dart' show
     UserOption;
 
+import 'settings.dart' show
+    alwaysRunInIframe,
+    communicateViaBlobs;
+
+bool isBrowserIE() {
+  return window.navigator.userAgent.contains(' Trident/7.0;');
+}
+
+initHiddenSettings() {
+  alwaysRunInIframe.setIfNotInitialized(isBrowserIE);
+  communicateViaBlobs.setIfNotInitialized(() => !isBrowserIE());
+}
+
 int count = 0;
 
 main() {
   UserOption.storage = window.localStorage;
   if (currentSource == null) {
     currentSource = EXAMPLE_HELLO;
   }
 
+  initHiddenSettings();
+
   buildUI();
   ReceivePort port = new ReceivePort();
   Isolate.spawnUri(
       Uri.base.resolve('compiler_isolate.dart.js'),
       const <String>[], port.sendPort).then((Isolate isolate) {
     LinkElement link = querySelector('link[rel="dart-sdk"]');
     String sdk = link.href;
     print('Using Dart SDK: $sdk');
     int messageCount = 0;
     SendPort sendPort;
@@ skipping 10 matching lines @@
           interaction.onMutation([], observer);
           break;
         default:
           // TODO(ahe): Close [port]?
           print('Unexpected message received: $message');
           break;
       }
     });
   });
 }