Delete site/try

site/try/iframe.js

-// 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.
-
-function dartPrint(msg) {
-  window.parent.postMessage(String(msg), "*");
-}
-
-window.onerror = function (message, url, lineNumber) {
-  window.parent.postMessage(
-      ["error", {message: message, url: url, lineNumber: lineNumber}], "*");
-};
-
-function onMessageReceived(event) {
-  var data = event.data;
-  if (data instanceof Array) {
-    if (data.length == 2 && data[0] == 'source') {
-      var script = document.createElement('script');
-      script.innerHTML = data[1];
-      script.type = 'application/javascript';
-      document.head.appendChild(script);
-      return;
-    }
-  }
-}
-
-window.addEventListener("message", onMessageReceived, false);
-
-(function () {
-  function postScrollHeight() {
-    window.parent.postMessage(
-      ["scrollHeight", document.documentElement.scrollHeight], "*");
-  }
-
-  var mutationObserverConstructor =
-      window.MutationObserver ||
-      window.WebKitMutationObserver ||
-      window.MozMutationObserver;
-
-  var observer = new mutationObserverConstructor(function(mutations) {
-    postScrollHeight()
-    window.setTimeout(postScrollHeight, 500);
-  });
-
-  observer.observe(
-      document.body,
-      { attributes: true,
-        childList: true,
-        characterData: true,
-        subtree: true });
-})();