Remove more oilpan.

sky/engine/wtf/ListHashSet.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, Benjamin Poulain <ikipou@gmail.com>
  *
  * 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 378 matching lines @@
             self->m_value.~ValueArg();
         }
 
         void destroy(NodeAllocator* allocator)
         {
             this->~ListHashSetNode();
             setWasAlreadyDestructed();
             allocator->deallocate(this);
         }
 
-        // This is not called in normal tracing, but it is called if we find a
-        // pointer to a node on the stack using conservative scanning. Since
-        // the original ListHashSet may no longer exist we make sure to mark
-        // the neighbours in the chain too.
-        void trace(typename NodeAllocator::Visitor* visitor)
-        {
-            // The conservative stack scan can find nodes that have been
-            // removed from the set and destructed. We don't need to trace
-            // these, and it would be wrong to do so, because the class will
-            // not expect the trace method to be called after the destructor.
-            // It's an error to remove a node from the ListHashSet while an
-            // iterator is positioned at that node, so there should be no valid
-            // pointers from the stack to a destructed node.
-            if (wasAlreadyDestructed())
-                return;
-            NodeAllocator::traceValue(visitor, this);
-            visitor->mark(next());
-            visitor->mark(prev());
-        }
-
         ListHashSetNode* next() const { return reinterpret_cast<ListHashSetNode*>(this->m_next); }
         ListHashSetNode* prev() const { return reinterpret_cast<ListHashSetNode*>(this->m_prev); }
 
         // Don't add fields here, the ListHashSetNodeBase and this should have
         // the same size.
 
         static ListHashSetNode* unlinkedNodePointer() { return reinterpret_cast<ListHashSetNode*>(-1); }
 
         template<typename HashArg>
         friend struct ListHashSetNodeHashFunctions;
@@ skipping 579 matching lines @@
     struct NeedsTracing<ListHashSet<T, U, V> > {
         static const bool value = false;
     };
 #endif
 
 } // namespace WTF
 
 using WTF::ListHashSet;
 
 #endif /* WTF_ListHashSet_h */