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

Source/platform/heap/PersistentNode.cpp

Index: Source/platform/heap/PersistentNode.cpp
diff --git a/Source/platform/heap/PersistentNode.cpp b/Source/platform/heap/PersistentNode.cpp
index 516ee02faca2b1a4a0c0fde7c2b799e416a540b9..6271f7d6ea72c36c01868d2a242d3f18b4db3406 100644
--- a/Source/platform/heap/PersistentNode.cpp
+++ b/Source/platform/heap/PersistentNode.cpp
@@ -31,25 +31,6 @@
     ASSERT(persistentCount == m_persistentCount);
     return persistentCount;
 }
-
-#if ENABLE(ASSERT)
-void PersistentRegion::dumpLivePersistents()
-{
-    class Object;
-    using GCObject = GarbageCollected<Object>;
-
-    fprintf(stderr, "Live Persistent(heap object, trace method):\n");
-    for (PersistentNodeSlots* slots = m_slots; slots; slots = slots->m_next) {
-        for (int i = 0; i < PersistentNodeSlots::slotCount; ++i) {
-            if (!slots->m_slot[i].isUnused()) {
-                Persistent<GCObject>* persistent = reinterpret_cast<Persistent<GCObject>*>(slots->m_slot[i].self());
-                ASSERT(persistent);
-                fprintf(stderr, "%p => (%p, %p)\n", persistent, persistent->get(), slots->m_slot[i].traceCallback());
-            }
-        }
-    }
-}
-#endif
 
 void PersistentRegion::ensurePersistentNodeSlots(void* self, TraceCallback trace)
 {