Improve DEFINE_STATIC_LOCAL()'s handling of Blink GCed objects.

third_party/WebKit/Source/core/dom/WeakIdentifierMap.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WeakIdentifierMap_h
 #define WeakIdentifierMap_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/Allocator.h"
 #include "wtf/HashMap.h"
@@ skipping 21 matching lines @@
 
 template<typename T,
     typename Generator = IdentifierGenerator<int>,
     typename Traits = WeakIdentifierMapTraits<T>,
     bool isGarbageCollected = IsGarbageCollectedType<T>::value> class WeakIdentifierMap;
 
 template<typename T, typename Generator, typename Traits> class WeakIdentifierMap<T, Generator, Traits, false> {
     USING_FAST_MALLOC(WeakIdentifierMap);
 public:
     using IdentifierType = typename Generator::IdentifierType;
-    using ReferenceType = RawPtr<WeakIdentifierMap<T, Generator, Traits, false>>;
 
     static IdentifierType identifier(T* object)
     {
         IdentifierType result = instance().m_objectToIdentifier.get(object);
 
         if (WTF::isHashTraitsEmptyValue<HashTraits<IdentifierType>>(result)) {
             result = Generator::next();
             instance().put(object, result);
         }
         return result;
@@ skipping 33 matching lines @@
     using IdentifierToObject = HashMap<IdentifierType, T*>;
 
     ObjectToIdentifier m_objectToIdentifier;
     IdentifierToObject m_identifierToObject;
 };
 
 template<typename T, typename Generator, typename Traits> class WeakIdentifierMap<T, Generator, Traits, true>
     : public GarbageCollected<WeakIdentifierMap<T, Generator, Traits, true>> {
 public:
     using IdentifierType = typename Generator::IdentifierType;
-    using ReferenceType = Persistent<WeakIdentifierMap<T, Generator, Traits, true>>;
 
     static IdentifierType identifier(T* object)
     {
         IdentifierType result = instance().m_objectToIdentifier->get(object);
 
         if (WTF::isHashTraitsEmptyValue<HashTraits<IdentifierType>>(result)) {
             result = Generator::next();
             instance().put(object, result);
         }
         return result;
@@ skipping 32 matching lines @@
     using IdentifierToObject = HeapHashMap<IdentifierType, WeakMember<T>>;
 
     Member<ObjectToIdentifier> m_objectToIdentifier;
     Member<IdentifierToObject> m_identifierToObject;
 };
 
 #define DECLARE_WEAK_IDENTIFIER_MAP(T, ...) \
     template<> WeakIdentifierMap<T, ##__VA_ARGS__>& WeakIdentifierMap<T, ##__VA_ARGS__>::instance(); \
     extern template class WeakIdentifierMap<T, ##__VA_ARGS__>;
 
-#define DEFINE_WEAK_IDENTIFIER_MAP(T, ...) \
+#define DEFINE_WEAK_IDENTIFIER_MAP(T, ...)   \
     template class WeakIdentifierMap<T, ##__VA_ARGS__>; \
     template<> WeakIdentifierMap<T, ##__VA_ARGS__>& WeakIdentifierMap<T, ##__VA_ARGS__>::instance() \
     { \
-        using RefType = WeakIdentifierMap<T, ##__VA_ARGS__>::ReferenceType; \
+        using RefType = WeakIdentifierMap<T, ##__VA_ARGS__>; \
         DEFINE_STATIC_LOCAL(RefType, mapInstance, (new WeakIdentifierMap<T, ##__VA_ARGS__>())); \
-        return *mapInstance; \
+        return mapInstance; \
     }
+
 } // namespace blink
 
 #endif // WeakIdentifierMap_h