Add #include <algorithm> to code that is missing it.

Source/wtf/RefPtr.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  *
  *  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,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Library General Public License for more details.
  *
  *  You should have received a copy of the GNU Library General Public License
  *  along with this library; see the file COPYING.LIB.  If not, write to
  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  *  Boston, MA 02110-1301, USA.
  *
  */
 
 // RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html
 
 #ifndef WTF_RefPtr_h
 #define WTF_RefPtr_h
 
-#include <algorithm>
 #include "wtf/HashTableDeletedValueType.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RawPtr.h"
+#include <algorithm> // For std::swap
 
 namespace WTF {
 
     template<typename T> class PassRefPtr;
 
     template<typename T> class RefPtr {
     public:
         ALWAYS_INLINE RefPtr() : m_ptr(0) { }
         ALWAYS_INLINE RefPtr(std::nullptr_t) : m_ptr(0) { }
         ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); }
@@ skipping 169 matching lines @@
     private:
         T* m_ptr;
     };
 
 } // namespace WTF
 
 using WTF::RefPtr;
 using WTF::static_pointer_cast;
 
 #endif // WTF_RefPtr_h