Remove virtual destructor for Pair class

Source/core/css/Pair.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 26 matching lines @@
     enum IdenticalValuesPolicy { DropIdenticalValues, KeepIdenticalValues };
 
     static PassRefPtr<Pair> create()
     {
         return adoptRef(new Pair);
     }
     static PassRefPtr<Pair> create(PassRefPtr<CSSPrimitiveValue> first, PassRefPtr<CSSPrimitiveValue> second, IdenticalValuesPolicy identicalValuesPolicy)
     {
         return adoptRef(new Pair(first, second, identicalValuesPolicy));
     }
-    virtual ~Pair() { }
 
     CSSPrimitiveValue* first() const { return m_first.get(); }
     CSSPrimitiveValue* second() const { return m_second.get(); }
     IdenticalValuesPolicy identicalValuesPolicy() const { return m_identicalValuesPolicy; }
 
     void setFirst(PassRefPtr<CSSPrimitiveValue> first) { m_first = first; }
     void setSecond(PassRefPtr<CSSPrimitiveValue> second) { m_second = second; }
     void setIdenticalValuesPolicy(IdenticalValuesPolicy identicalValuesPolicy) { m_identicalValuesPolicy = identicalValuesPolicy; }
 
     String cssText() const
@@ skipping 37 matching lines @@
     }
 
     RefPtr<CSSPrimitiveValue> m_first;
     RefPtr<CSSPrimitiveValue> m_second;
     IdenticalValuesPolicy m_identicalValuesPolicy;
 };
 
 } // namespace
 
 #endif