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

Source/wtf/HashTraits.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserved.
  *
  * 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 57 matching lines @@
     };
 
     template<typename T> struct GenericHashTraits : GenericHashTraitsBase<IsInteger<T>::value, T> {
         typedef T TraitType;
         typedef T EmptyValueType;
 
         static T emptyValue() { return T(); }
 
         // Type for functions that do not take ownership, such as contains.
         typedef const T& PeekInType;
+        typedef T* IteratorGetType;
+        typedef const T* IteratorConstGetType;
+        typedef T& IteratorReferenceType;
+        typedef const T& IteratorConstReferenceType;
+        static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
+        static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
         // Type for functions that take ownership, such as add.
         // The store function either not be called or called once to store something passed in.
         // The value passed to the store function will be PassInType.
         typedef const T& PassInType;
         static void store(const T& value, T& storage) { storage = value; }
 
         // Type for return value of functions that transfer ownership, such as take. 
         typedef T PassOutType;
         static PassOutType passOut(const T& value) { return value; }
 
@@ skipping 37 matching lines @@
         static void constructDeletedValue(T& slot) { new (NotNull, &slot) T(HashTableDeletedValue); }
         static bool isDeletedValue(const T& value) { return value.isHashTableDeletedValue(); }
     };
 
     template<typename P> struct HashTraits<OwnPtr<P> > : SimpleClassHashTraits<OwnPtr<P> > {
         typedef std::nullptr_t EmptyValueType;
 
         static EmptyValueType emptyValue() { return nullptr; }
 
         typedef const OwnPtr<P>& PeekInType;
+        typedef P* IteratorGetType;
+        typedef const P* IteratorConstGetType;
+        typedef P& IteratorReferenceType;
+        typedef const P& IteratorConstReferenceType;
+        static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
+        static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
         typedef PassOwnPtr<P> PassInType;
         static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) { storage = value; }
 
         typedef PassOwnPtr<P> PassOutType;
         static PassOwnPtr<P> passOut(OwnPtr<P>& value) { return value.release(); }
         static PassOwnPtr<P> passOut(std::nullptr_t) { return nullptr; }
 
         typedef typename OwnPtr<P>::PtrType PeekType;
         static PeekType peek(const OwnPtr<P>& value) { return value.get(); }
         static PeekType peek(std::nullptr_t) { return 0; }
     };
 
     template<typename P> struct HashTraits<RefPtr<P> > : SimpleClassHashTraits<RefPtr<P> > {
         typedef const RefPtr<P>& PeekInType;
+        typedef RefPtr<P>* IteratorGetType;
+        typedef const RefPtr<P>* IteratorConstGetType;
+        typedef RefPtr<P>& IteratorReferenceType;
+        typedef const RefPtr<P>& IteratorConstReferenceType;
+        static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { return *x; }
+        static IteratorConstReferenceType getToReferenceConstConversion(IteratorConstGetType x) { return *x; }
         typedef PassRefPtr<P> PassInType;
         static void store(PassRefPtr<P> value, RefPtr<P>& storage) { storage = value; }
 
         // FIXME: We should change PassOutType to PassRefPtr for better performance.
         // FIXME: We should consider changing PeekType to a raw pointer for better performance,
         // but then callers won't need to call get; doing so will require updating many call sites.
     };
 
     template<> struct HashTraits<String> : SimpleClassHashTraits<String> {
         static const bool hasIsEmptyValueFunction = true;
@@ skipping 89 matching lines @@
     };
 
 } // namespace WTF
 
 using WTF::HashTraits;
 using WTF::PairHashTraits;
 using WTF::NullableHashTraits;
 using WTF::SimpleClassHashTraits;
 
 #endif // WTF_HashTraits_h