Update modules classes to use OVERRIDE / FINAL when needed

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 19 matching lines @@
 #include "wtf/PassRefPtr.h"
 #include "wtf/Threading.h"
 
 namespace WebCore {
 
 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 : public AudioNode {
+class GainNode FINAL : public AudioNode {
 public:
     static PassRefPtr<GainNode> create(AudioContext* context, float sampleRate)
     {
         return adoptRef(new GainNode(context, sampleRate));
     }
 
     // AudioNode
-    virtual void process(size_t framesToProcess);
-    virtual void reset();
+    virtual void process(size_t framesToProcess) OVERRIDE;
+    virtual void reset() OVERRIDE;
 
     // Called in the main thread when the number of channels for the input may have changed.
-    virtual void checkNumberOfChannelsForInput(AudioNodeInput*);
+    virtual void checkNumberOfChannelsForInput(AudioNodeInput*) OVERRIDE;
 
     // JavaScript interface
     AudioParam* gain() { return m_gain.get(); }
 
 private:
     virtual double tailTime() const OVERRIDE { return 0; }
     virtual double latencyTime() const OVERRIDE { return 0; }
 
     GainNode(AudioContext*, float sampleRate);
 
     float m_lastGain; // for de-zippering
     RefPtr<AudioParam> m_gain;
 
     AudioFloatArray m_sampleAccurateGainValues;
 };
 
 } // namespace WebCore
 
 #endif // GainNode_h