Devirtualize several mediastream class destructors

Source/modules/mediastream/NavigatorUserMediaError.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 26 matching lines @@
     enum Name {
         NamePermissionDenied,
         NameConstraintNotSatisfied
     };
 
     static PassRefPtr<NavigatorUserMediaError> create(Name name, const String& message, const String& constraintName)
     {
         return adoptRef(new NavigatorUserMediaError(name, message, constraintName));
     }
 
-    virtual ~NavigatorUserMediaError() { }
-
     String name() const;
     const String& message() const { return m_message; }
     const String& constraintName() const { return m_constraintName; }
 
 private:
     NavigatorUserMediaError(Name name, const String& message, const String& constraintName)
         : m_name(name), m_message(message), m_constraintName(constraintName)
     {
         ScriptWrappable::init(this);
     }
 
     Name m_name;
     String m_message;
     String m_constraintName;
 };
 
 } // namespace WebCore
 
 #endif // NavigatorUserMediaError_h