Clean up forward declarations in Source/modules

Source/modules/webaudio/AudioBasicProcessorNode.h

 /*
  * Copyright (C) 2010, 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 13 matching lines @@
 
 #ifndef AudioBasicProcessorNode_h
 #define AudioBasicProcessorNode_h
 
 #include "modules/webaudio/AudioNode.h"
 #include "wtf/Forward.h"
 #include "wtf/Threading.h"
 
 namespace blink {
 
-class AudioBus;
 class AudioNodeInput;
 class AudioProcessor;
 
 // AudioBasicProcessorNode is an AudioNode with one input and one output where the input and output have the same number of channels.
 class AudioBasicProcessorNode : public AudioNode {
 public:
     AudioBasicProcessorNode(AudioContext*, float sampleRate);
     virtual ~AudioBasicProcessorNode();
     virtual void trace(Visitor*) override;
 
@@ skipping 14 matching lines @@
     virtual double tailTime() const override final;
     virtual double latencyTime() const override final;
 
     AudioProcessor* processor() { return m_processor.get(); }
     Member<AudioProcessor> m_processor;
 };
 
 } // namespace blink
 
 #endif // AudioBasicProcessorNode_h