Oilpan: catch some self-referential leaks (main thread.)

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 930 matching lines @@
     }
 
     SelfKeepAlive& operator=(Self* self)
     {
         assign(self);
         return *this;
     }
 
     void clear()
     {
+#if ENABLE(ASSERT)
+        if (m_keepAlive)
+            ThreadState::decrementSelfKeepAliveAllocations();
+#endif
         m_keepAlive.clear();
     }
 
     typedef OwnPtr<Persistent<Self>> (SelfKeepAlive::*UnspecifiedBoolType);
     operator UnspecifiedBoolType() const { return m_keepAlive ? &SelfKeepAlive::m_keepAlive : 0; }
 
 private:
     void assign(Self* self)
     {
         ASSERT(!m_keepAlive || m_keepAlive->get() == self);
-        if (!m_keepAlive)
+        if (!m_keepAlive) {
             m_keepAlive = adoptPtr(new Persistent<Self>);
+#if ENABLE(ASSERT)
+            ThreadState::incrementSelfKeepAliveAllocations();
+#endif
+        }
         *m_keepAlive = self;
     }
 
     GC_PLUGIN_IGNORE("420515")
     OwnPtr<Persistent<Self>> m_keepAlive;
 };
 
 } // namespace blink
 
 namespace WTF {
@@ skipping 183 matching lines @@
 struct ParamStorageTraits<RawPtr<T>> : public PointerParamStorageTraits<T*, blink::IsGarbageCollectedType<T>::value> {
     static_assert(sizeof(T), "T must be fully defined");
 };
 
 template<typename T>
 PassRefPtr<T> adoptRef(blink::RefCountedGarbageCollected<T>*) = delete;
 
 } // namespace WTF
 
 #endif