Turn on webaudio for JS backends.

client/dom/generated/src/wrapping/_AudioBufferWrappingImplementation.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 _AudioBufferWrappingImplementation extends DOMWrapperBase implements AudioBuffer {
+  _AudioBufferWrappingImplementation() : super() {}
+
+  static create__AudioBufferWrappingImplementation() native {
+    return new _AudioBufferWrappingImplementation();
+  }
+
+  num get duration() { return _get_duration(this); }
+  static num _get_duration(var _this) native;
+
+  num get gain() { return _get_gain(this); }
+  static num _get_gain(var _this) native;
+
+  void set gain(num value) { _set_gain(this, value); }
+  static void _set_gain(var _this, num value) native;
+
+  int get length() { return _get_length(this); }
+  static int _get_length(var _this) native;
+
+  int get numberOfChannels() { return _get_numberOfChannels(this); }
+  static int _get_numberOfChannels(var _this) native;
+
+  num get sampleRate() { return _get_sampleRate(this); }
+  static num _get_sampleRate(var _this) native;
+
+  Float32Array getChannelData(int channelIndex) {
+    return _getChannelData(this, channelIndex);
+  }
+  static Float32Array _getChannelData(receiver, channelIndex) native;
+
+  String get typeName() { return "AudioBuffer"; }
+}