Safely wrap window.top in frog dom.

client/dom/generated/src/wrapping/_AudioContextWrappingImplementation.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 _AudioContextWrappingImplementation extends DOMWrapperBase implements AudioContext {
   _AudioContextWrappingImplementation() : super() {}
 
   static create__AudioContextWrappingImplementation() native {
@@ skipping 106 matching lines @@
     return _createPanner(this);
   }
   static AudioPannerNode _createPanner(receiver) native;
 
   WaveShaperNode createWaveShaper() {
     return _createWaveShaper(this);
   }
   static WaveShaperNode _createWaveShaper(receiver) native;
 
   void decodeAudioData(ArrayBuffer audioData, AudioBufferCallback successCallback, [AudioBufferCallback errorCallback = null]) {
-    if (errorCallback === null) {
-      _decodeAudioData(this, audioData, successCallback);
-      return;
-    } else {
-      _decodeAudioData_2(this, audioData, successCallback, errorCallback);
-      return;
-    }
+    _decodeAudioData(this, audioData, successCallback, errorCallback);
+    return;
   }
-  static void _decodeAudioData(receiver, audioData, successCallback) native;
-  static void _decodeAudioData_2(receiver, audioData, successCallback, errorCallback) native;
+  static void _decodeAudioData(receiver, audioData, successCallback, errorCallback) native;
 
   void startRendering() {
     _startRendering(this);
     return;
   }
   static void _startRendering(receiver) native;
 
   String get typeName() { return "AudioContext"; }
 }