Restrict the scope of PointerFieldStorageTrait<>.

third_party/WebKit/Source/platform/heap/Handle.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1178 matching lines @@
     private:
 
 #define DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(type) \
     type::~type() { }
 
 #define DEFINE_STATIC_REF_WILL_BE_PERSISTENT(type, name, arguments) \
     DEFINE_STATIC_REF(type, name, arguments)
 
 #endif // ENABLE(OILPAN)
 
-template<typename T, bool = IsGarbageCollectedType<T>::value>
-class PointerFieldStorageTrait {
-public:
-    using Type = RawPtr<T>;
-};
-
-template<typename T>
-class PointerFieldStorageTrait<T, true> {
-public:
-    using Type = Member<T>;
-};
-
 // Abstraction for injecting calls to an object's 'dispose()' method
 // on leaving a stack scope, ensuring earlier release of resources
 // than waiting until the object is eventually GCed.
 template<typename T, void (T::*Disposer)() = (&T::dispose)>
 class ScopedDisposal {
     STACK_ALLOCATED();
 public:
     ScopedDisposal(T* object)
         : m_object(object)
     {
     }
 
     ~ScopedDisposal()
     {
         if (m_object)
             (m_object->*Disposer)();
     }
 
     void clear() { m_object.clear(); }
 
 private:
+    template<typename U, bool = IsGarbageCollectedType<U>::value>
+    class PointerFieldStorageTrait {
+    public:
+        using Type = RawPtr<U>;
+    };
+
+    template<typename U>
+    class PointerFieldStorageTrait<U, true> {
+    public:
+        using Type = Member<U>;
+    };
+
     typename PointerFieldStorageTrait<T>::Type m_object;
 };
 
 // SelfKeepAlive<Object> is the idiom to use for objects that have to keep
 // themselves temporarily alive and cannot rely on there being some
 // external reference in that interval:
 //
 //  class Opener {
 //  public:
 //     ...
@@ skipping 331 matching lines @@
     static_assert(sizeof(T), "T must be fully defined");
     using StorageType = blink::CrossThreadWeakPersistent<T>;
 
     static StorageType wrap(const blink::AllowCrossThreadWeakPersistent<T>& value) { return value.value(); }
 
     // Currently assume that the call sites of this unwrap() account for cleared weak references also.
     // TODO(sof): extend WTF::FunctionWrapper call overloading to also handle (CrossThread)WeakPersistent.
     static T* unwrap(const StorageType& value) { return value.get(); }
 };
 
+// Adoption is not needed nor wanted for RefCountedGarbageCollected<>-derived types.
 template<typename T>
 PassRefPtr<T> adoptRef(blink::RefCountedGarbageCollected<T>*) = delete;
 
 } // namespace WTF
 
 #endif