bindings: Adds virtual ScriptWrappable::wrap method.

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 20 matching lines @@
 #include "wtf/Threading.h"
 
 namespace blink {
 
 class AudioContext;
 
 // 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 GainNode FINAL : public AudioNode {
+    DEFINE_WRAPPERTYPEINFO();
 public:
     static GainNode* create(AudioContext* context, float sampleRate)
     {
         return adoptRefCountedGarbageCollectedWillBeNoop(new GainNode(context, sampleRate));
     }
 
     // AudioNode
     virtual void process(size_t framesToProcess) OVERRIDE;
 
     // Called in the main thread when the number of channels for the input may have changed.
@@ skipping 12 matching lines @@
 
     float m_lastGain; // for de-zippering
     Member<AudioParam> m_gain;
 
     AudioFloatArray m_sampleAccurateGainValues;
 };
 
 } // namespace blink
 
 #endif // GainNode_h