Change hasSubscribers to hasListener.

sdk/lib/web_audio/dart2js/web_audio_dart2js.dart

 library dart.dom.web_audio;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:_js_helper' show Creates, Returns, convertDartClosureToJS;
 import 'dart:_foreign_helper' show JS;
 // DO NOT EDIT - unless you are editing documentation as per:
 // https://code.google.com/p/dart/wiki/ContributingHTMLDocumentation
@@ skipping 809 matching lines @@
    * Get a Stream that fires events when AudioProcessingEvents occur.
    * This particular stream is special in that it only allows one listener to a
    * given stream. Converting the returned Stream [asBroadcast] will likely ruin
    * the soft-real-time properties which which these events are fired and can
    * be processed.
    */
   Stream<AudioProcessingEvent> get onAudioProcess {
     if (_eventStream == null) {
       var controller = new StreamController();
       var callback = (audioData) { 
-          if (controller.hasSubscribers) {
+          if (controller.hasListener) {
             // This stream is a strange combination of broadcast and single
             // subscriber streams. We only allow one listener, but if there is
             // no listener, we don't queue up events, we just drop them on the
             // floor.
             controller.add(audioData);
           }
         };
       _setEventListener(callback);
       _eventStream = controller.stream;
     }
@@ skipping 28 matching lines @@
 }
 // 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.
 
 
 @DocsEditable
 @DomName('WaveTable')
 class WaveTable native "*WaveTable" {
 }