Remove more bits of the Oilpan tracing system

sky/engine/wtf/ListHashSet.h

Index: sky/engine/wtf/ListHashSet.h
diff --git a/sky/engine/wtf/ListHashSet.h b/sky/engine/wtf/ListHashSet.h
index 1b8515a5798642fe96ff4e1ae77e57d92ab34e1e..068eb7d3bf5d4c501479feef7abba389925a4055 100644
--- a/sky/engine/wtf/ListHashSet.h
+++ b/sky/engine/wtf/ListHashSet.h
@@ -185,8 +185,6 @@ namespace WTF {
         ValuePassOutType take(ValuePeekInType);
         ValuePassOutType takeFirst();
 
-        void trace(typename Allocator::Visitor*);
-
     private:
         void unlink(Node*);
         void unlinkAndDelete(Node*);
@@ -330,8 +328,6 @@ namespace WTF {
             return node >= pool() && node < pastPool();
         }
 
-        static void traceValue(typename DefaultAllocator::Visitor* visitor, Node* node) { }
-
     private:
         Node* pool() { return reinterpret_cast_ptr<Node*>(m_pool.buffer); }
         Node* pastPool() { return pool() + m_poolSize; }
@@ -973,23 +969,6 @@ namespace WTF {
             node->destroy(this->allocator());
     }
 
-    template<typename T, size_t inlineCapacity, typename U, typename V>
-    void ListHashSet<T, inlineCapacity, U, V>::trace(typename Allocator::Visitor* visitor)
-    {
-        COMPILE_ASSERT(HashTraits<T>::weakHandlingFlag == NoWeakHandlingInCollections, ListHashSetDoesNotSupportWeakness);
-        // This marks all the nodes and their contents live that can be
-        // accessed through the HashTable. That includes m_head and m_tail
-        // so we do not have to explicitly trace them here.
-        m_impl.trace(visitor);
-    }
-
-#if !ENABLE(OILPAN)
-    template<typename T, size_t U, typename V>
-    struct NeedsTracing<ListHashSet<T, U, V> > {
-        static const bool value = false;
-    };
-#endif
-
 } // namespace WTF
 
 using WTF::ListHashSet;