[oilpan] Fix iterators over member collections to return Result<T>

Source/wtf/HashSet.h

Index: Source/wtf/HashSet.h
diff --git a/Source/wtf/HashSet.h b/Source/wtf/HashSet.h
index 864578df80de30205f7574925148c68a9bb3ac16..34552aafacbf04ccc0f8a91e1591547059bfd3a4 100644
--- a/Source/wtf/HashSet.h
+++ b/Source/wtf/HashSet.h
@@ -59,8 +59,8 @@ namespace WTF {
     public:
         typedef typename Allocator::template IteratorWitness<HashSet>::Type IteratorWitnessType;
         typedef typename Allocator::DefaultArgument DefaultWitnessType;
-        typedef HashTableConstIteratorAdapter<HashTableType, ValueType> iterator;
-        typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;
+        typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> iterator;
+        typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> const_iterator;
         typedef typename HashTableType::AddResult AddResult;
 
         void swap(HashSet&);