Ensure proper finalization of garbage-collected types.

Source/platform/Supplementable.h

 /*
  * Copyright (C) 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 101 matching lines @@
 template<bool>
 class SupplementTracing;
 
 template<>
 class SupplementTracing<true> : public GarbageCollectedMixin {
 public:
     virtual void trace(Visitor*) = 0;
 };
 
 template<>
-class SupplementTracing<false> { };
+class SupplementTracing<false> {
+public:
+    virtual ~SupplementTracing() { }
+};
 
 template<typename T, bool isGarbageCollected = false>
 class SupplementBase : public SupplementTracing<isGarbageCollected> {
 public:
-    virtual ~SupplementBase() { }
 #if SECURITY_ASSERT_ENABLED
     virtual bool isRefCountedWrapper() const { return false; }
 #endif
 
     static void provideTo(SupplementableBase<T, isGarbageCollected>& host, const char* key, typename SupplementableTraits<T, isGarbageCollected>::SupplementArgumentType supplement)
     {
         host.provideSupplement(key, supplement);
     }
 
     static SupplementBase<T, isGarbageCollected>* from(SupplementableBase<T, isGarbageCollected>& host, const char* key)
@@ skipping 83 matching lines @@
 };
 
 template<typename T>
 struct ThreadingTrait<WebCore::SupplementableBase<T, true> > {
     static const ThreadAffinity Affinity = ThreadingTrait<T>::Affinity;
 };
 
 } // namespace WebCore
 
 #endif // Supplementable_h