Revert of [Oilpan] Prepare full definition of classes before using Member

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 753 matching lines @@
         m_raw = nullptr;
         return *this;
     }
 
     void swap(Member<T>& other)
     {
         std::swap(m_raw, other.m_raw);
         checkPointer();
     }
 
-    T* get() const
-    {
-        static_assert(IsFullyDefined<T>::value, "T is not fully defined.");
-        return m_raw;
-    }
+    T* get() const { return m_raw; }
 
     void clear() { m_raw = nullptr; }
 
 
 protected:
     void checkPointer()
     {
-        static_assert(IsFullyDefined<T>::value, "T is not fully defined.");
-
 #if ENABLE(ASSERT) && defined(ADDRESS_SANITIZER)
         if (!m_raw)
             return;
         // HashTable can store a special value (which is not aligned to the
         // allocation granularity) to Member<> to represent a deleted entry.
         // Thus we treat a pointer that is not aligned to the granularity
         // as a valid pointer.
         if (reinterpret_cast<intptr_t>(m_raw) % allocationGranularity)
             return;
 
@@ skipping 712 matching lines @@
     // TODO(sof): extend WTF::FunctionWrapper call overloading to also handle (CrossThread)WeakPersistent.
     static T* unwrap(const StorageType& value) { return value.get(); }
 };
 
 template<typename T>
 PassRefPtr<T> adoptRef(blink::RefCountedGarbageCollected<T>*) = delete;
 
 } // namespace WTF
 
 #endif