Unify and generalize thread static persistent finalization.

third_party/WebKit/Source/platform/heap/PersistentNode.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 PersistentNode_h
 #define PersistentNode_h
 
 #include "platform/PlatformExport.h"
 #include "platform/heap/ThreadState.h"
 #include "wtf/Allocator.h"
@@ skipping 121 matching lines @@
 #endif
         if (UNLIKELY(!m_freeListHead))
             ensurePersistentNodeSlots(self, trace);
         ASSERT(m_freeListHead);
         PersistentNode* node = m_freeListHead;
         m_freeListHead = m_freeListHead->freeListNext();
         node->initialize(self, trace);
         ASSERT(!node->isUnused());
         return node;
     }
+
     void freePersistentNode(PersistentNode* persistentNode)
     {
         ASSERT(m_persistentCount > 0);
         persistentNode->setFreeListNext(m_freeListHead);
         m_freeListHead = persistentNode;
 #if ENABLE(ASSERT)
         --m_persistentCount;
 #endif
     }
 
     static bool shouldTracePersistentNode(Visitor*, PersistentNode*) { return true; }
 
     using ShouldTraceCallback = bool (*)(Visitor*, PersistentNode*);
     void tracePersistentNodes(Visitor*, ShouldTraceCallback = PersistentRegion::shouldTracePersistentNode);
+
+    void releasePersistentNode(PersistentNode*, ThreadState::PersistentClearCallback);
     int numberOfPersistents();
 
 private:
     friend CrossThreadPersistentRegion;
 
     void ensurePersistentNodeSlots(void*, TraceCallback);
 
     PersistentNode* m_freeListHead;
     PersistentNodeSlots* m_slots;
 #if ENABLE(ASSERT)
@@ skipping 32 matching lines @@
     // We don't make CrossThreadPersistentRegion inherit from PersistentRegion
     // because we don't want to virtualize performance-sensitive methods
     // such as PersistentRegion::allocate/freePersistentNode.
     OwnPtr<PersistentRegion> m_persistentRegion;
     Mutex m_mutex;
 };
 
 } // namespace blink
 
 #endif