Avoid needless InstanceCounter.h inclusion.

third_party/WebKit/Source/wtf/RefCounted.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 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.
  *
  */
 
 #ifndef RefCounted_h
 #define RefCounted_h
 
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
-#include "wtf/InstanceCounter.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/WTFExport.h"
 
+#if ENABLE(INSTANCE_COUNTER)
+#include "wtf/InstanceCounter.h"
+#endif
+
 #if DCHECK_IS_ON()
 #define CHECK_REF_COUNTED_LIFECYCLE 1
 #include "wtf/ThreadRestrictionVerifier.h"
 #else
 #define CHECK_REF_COUNTED_LIFECYCLE 0
 #endif
 
 namespace WTF {
 
 // This base class holds the non-template methods and attributes.
@@ skipping 105 matching lines @@
   // new.
   USING_FAST_MALLOC(T);
 
  public:
   void deref() const {
     if (derefBase())
       delete static_cast<const T*>(this);
   }
 
  protected:
-#ifdef ENABLE_INSTANCE_COUNTER
+#if ENABLE(INSTANCE_COUNTER)
   RefCounted() { incrementInstanceCount<T>(static_cast<T*>(this)); }
 
   ~RefCounted() { decrementInstanceCount<T>(static_cast<T*>(this)); }
 #else
   RefCounted() {}
 #endif
 };
 
 }  // namespace WTF
 
 using WTF::RefCounted;
 
 #endif  // RefCounted_h