Report precise memory usage from StaticNodeList to v8

Source/core/dom/StaticNodeList.h

 /*
  * Copyright (C) 2007, 2008 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
@@ skipping 38 matching lines @@
     }
 
     virtual ~StaticNodeList();
 
     virtual unsigned length() const OVERRIDE;
     virtual Node* item(unsigned index) const OVERRIDE;
 
     virtual void trace(Visitor*) OVERRIDE;
 
 private:
-    // If AllocationSize() is larger than this, we report it as external
-    // allocated memory to V8.
-    const static ptrdiff_t externalMemoryReportSizeLimit = 1024;
-
     ptrdiff_t AllocationSize()
     {
         return m_nodes.capacity() * sizeof(RefPtrWillBeMember<Node>);
     }
 
     WillBeHeapVector<RefPtrWillBeMember<Node> > m_nodes;
 };
 
 } // namespace WebCore
 
 #endif // StaticNodeList_h