Remove AudioSourceNode class

third_party/WebKit/Source/modules/webaudio/MediaElementAudioSourceNode.idl

 /*
  * Copyright (C) 2011, Google 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  * DAMAGE.
  */
 
 // See https://webaudio.github.io/web-audio-api/#MediaElementAudioSourceNode
 [
     // TODO(rtoy): This should be AudioContext, not BaseAudioContext.
     Constructor(BaseAudioContext context, MediaElementAudioSourceOptions options),
     RaisesException=Constructor,
     Measure
 ]
-interface MediaElementAudioSourceNode : AudioSourceNode {
+interface MediaElementAudioSourceNode : AudioNode {
     readonly attribute HTMLMediaElement mediaElement;
 };