Turn on webaudio for JS backends.

client/dom/generated/src/wrapping/_AudioBufferCallbackWrappingImplementation.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 _AudioBufferCallbackWrappingImplementation extends DOMWrapperBase implements AudioBufferCallback {
+  _AudioBufferCallbackWrappingImplementation() : super() {}
+
+  static create__AudioBufferCallbackWrappingImplementation() native {
+    return new _AudioBufferCallbackWrappingImplementation();
+  }
+
+  bool handleEvent(AudioBuffer audioBuffer) {
+    return _handleEvent(this, audioBuffer);
+  }
+  static bool _handleEvent(receiver, audioBuffer) native;
+
+  String get typeName() { return "AudioBufferCallback"; }
+}