Safely wrap window.top in frog dom.

client/dom/generated/src/wrapping/_NavigatorWrappingImplementation.dart

 // Copyright (c) 2011, 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.
 
 // WARNING: Do not edit - generated code.
 
 class _NavigatorWrappingImplementation extends DOMWrapperBase implements Navigator {
   _NavigatorWrappingImplementation() : super() {}
 
   static create__NavigatorWrappingImplementation() native {
@@ skipping 56 matching lines @@
   }
   static bool _javaEnabled(receiver) native;
 
   void registerProtocolHandler(String scheme, String url, String title) {
     _registerProtocolHandler(this, scheme, url, title);
     return;
   }
   static void _registerProtocolHandler(receiver, scheme, url, title) native;
 
   void webkitGetUserMedia(String options, NavigatorUserMediaSuccessCallback successCallback, [NavigatorUserMediaErrorCallback errorCallback = null]) {
-    if (errorCallback === null) {
-      _webkitGetUserMedia(this, options, successCallback);
-      return;
-    } else {
-      _webkitGetUserMedia_2(this, options, successCallback, errorCallback);
-      return;
-    }
+    _webkitGetUserMedia(this, options, successCallback, errorCallback);
+    return;
   }
-  static void _webkitGetUserMedia(receiver, options, successCallback) native;
-  static void _webkitGetUserMedia_2(receiver, options, successCallback, errorCallback) native;
+  static void _webkitGetUserMedia(receiver, options, successCallback, errorCallback) native;
 
   String get typeName() { return "Navigator"; }
 }