AudioContext.decodeAudioData returns a Promise

Source/modules/webaudio/AudioContext.idl

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 38 matching lines @@
 
     // All panning is relative to this listener.
     readonly attribute AudioListener listener;
 
     // Current state of the AudioContext
     readonly attribute AudioContextState state;
 
     [RaisesException] AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long numberOfFrames, float sampleRate);
 
     // Asynchronous audio file data decoding.
-    [RaisesException, MeasureAs=AudioContextDecodeAudioData] void decodeAudioData(ArrayBuffer audioData, AudioBufferCallback successCallback, optional AudioBufferCallback errorCallback);
+    [RaisesException, CallWith=ScriptState, MeasureAs=AudioContextDecodeAudioData] Promise<AudioBuffer> decodeAudioData(ArrayBuffer audioData, optional AudioBufferCallback successCallback, optional AudioBufferCallback errorCallback);
 
     // Sources
     [RaisesException, MeasureAs=AudioContextCreateBufferSource] AudioBufferSourceNode createBufferSource();
 
     [RaisesException, MeasureAs=AudioContextCreateMediaElementSource] MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
 
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamSource, RaisesException] MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamDestination] MediaStreamAudioDestinationNode createMediaStreamDestination();
 
     // Processing nodes
@@ skipping 16 matching lines @@
 
     // Close
     [MeasureAs=AudioContextClose, CallWith=ScriptState, ImplementedAs=closeContext] Promise<void> close();
 
     // Pause/resume
     [MeasureAs=AudioContextSuspend, CallWith=ScriptState, ImplementedAs=suspendContext] Promise<void> suspend();
     [MeasureAs=AudioContextResume, CallWith=ScriptState, ImplementedAs=resumeContext] Promise<void> resume();
 
     attribute EventHandler onstatechange;
 };