Get rid of Dynamic.

lib/html/src/dart2js_DOMImplementation.dart

 // Copyright (c) 2012, 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.
 
 // TODO(vsm): Unify with Dartium version.
 class _DOMWindowCrossFrameImpl implements Window {
   // Private window.  Note, this is a window in another frame, so it
   // cannot be typed as "Window" as its prototype is not patched
   // properly.  Its fields and methods can only be accessed via JavaScript.
   var _window;
@@ skipping 14 matching lines @@
 
   Window get top => _createSafe(JS('Window', '#.top', _window));
 
   // Methods.
   void focus() => JS('void', '#.focus()', _window);
 
   void blur() => JS('void', '#.blur()', _window);
 
   void close() => JS('void', '#.close()', _window);
 
-  void postMessage(Dynamic message,
-                   String targetOrigin,
-                   [List messagePorts = null]) {
+  void postMessage(var message, String targetOrigin, [List messagePorts = null]) {
     if (messagePorts == null) {
       JS('void', '#.postMessage(#,#)', _window, message, targetOrigin);
     } else {
       JS('void', '#.postMessage(#,#,#)', _window, message, targetOrigin, messagePorts);
     }
   }
 
   // Implementation support.
   _DOMWindowCrossFrameImpl(this._window);
 
@@ skipping 48 matching lines @@
 
   static History _createSafe(h) {
     if (identical(h, window.history)) {
       return h;
     } else {
       // TODO(vsm): Cache or implement equality.
       return new _HistoryCrossFrameImpl(h);
     }
   }
 }