Remove the WEB_AUDIO compile time flag

third_party/WebKit/Source/modules/webaudio/AudioBufferCallback.h

 /*
  * 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 10 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef AudioBufferCallback_h
 #define AudioBufferCallback_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/build_config.h"
 
-#if ENABLE(WEB_AUDIO)
-
 namespace blink {
 
 class AudioBuffer;
 
 class AudioBufferCallback : public GarbageCollectedFinalized<AudioBufferCallback> {
 public:
     virtual ~AudioBufferCallback() { }
     DEFINE_INLINE_VIRTUAL_TRACE() { }
     virtual void handleEvent(AudioBuffer*) = 0;
 };
 
 } // namespace
 
-#endif // ENABLE(WEB_AUDIO)
-
 #endif // AudioBufferCallback_h