include RefCounted.h where needed, only.

third_party/WebKit/Source/platform/PODFreeListArena.h

 /*
  * Copyright (C) 2011 Apple 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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PODFreeListArena_h
 #define PODFreeListArena_h
 
 #include "platform/PODArena.h"
 #include "wtf/Allocator.h"
+#include "wtf/RefCounted.h"
 
 namespace blink {
 
 template <class T>
 class PODFreeListArena : public RefCounted<PODFreeListArena<T>> {
 public:
     static PassRefPtr<PODFreeListArena> create()
     {
         return adoptRef(new PODFreeListArena);
     }
@@ skipping 82 matching lines @@
 
     static_assert(sizeof(T) >= sizeof(FixedSizeMemoryChunk), "PODFreeListArena type should be larger");
 
     friend class WTF::RefCounted<PODFreeListArena>;
     friend class PODFreeListArenaTest;
 };
 
 } // namespace blink
 
 #endif