Remove the WEB_AUDIO compile time flag

third_party/WebKit/Source/modules/webaudio/GainNode.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 12 matching lines @@
  */
 
 #ifndef GainNode_h
 #define GainNode_h
 
 #include "modules/webaudio/AudioNode.h"
 #include "modules/webaudio/AudioParam.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/Threading.h"
 
-#if ENABLE(WEB_AUDIO)
-
 namespace blink {
 
 class AbstractAudioContext;
 
 // GainNode is an AudioNode with one input and one output which applies a gain (volume) change to the audio signal.
 // De-zippering (smoothing) is applied when the gain value is changed dynamically.
 
 class GainHandler final : public AudioHandler {
 public:
     static PassRefPtr<GainHandler> create(AudioNode&, float sampleRate, AudioParamHandler& gain);
@@ skipping 22 matching lines @@
     AudioParam* gain() const;
 
 private:
     GainNode(AbstractAudioContext&, float sampleRate);
 
     Member<AudioParam> m_gain;
 };
 
 } // namespace blink
 
-#endif // ENABLE(WEB_AUDIO)
-
 #endif // GainNode_h