AudioContext.decodeAudioData returns a Promise

Source/modules/webaudio/AudioContext.idl

Index: Source/modules/webaudio/AudioContext.idl
diff --git a/Source/modules/webaudio/AudioContext.idl b/Source/modules/webaudio/AudioContext.idl
index 796254097c7b85a37480f88a7c9c9a7f2975c47d..87943bf3771d1e40a92251966a6a04b7a7f073a9 100644
--- a/Source/modules/webaudio/AudioContext.idl
+++ b/Source/modules/webaudio/AudioContext.idl
@@ -56,7 +56,7 @@ enum AudioContextState {
     [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();