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

Source/platform/heap/ThreadState.h

Index: Source/platform/heap/ThreadState.h
diff --git a/Source/platform/heap/ThreadState.h b/Source/platform/heap/ThreadState.h
index 0c015aeee37db03a46d4f7c03e250cddb3e39ba8..67486a140f72a93fd6b8c6f9c58a1fc71b9ece9a 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -652,6 +652,11 @@ public:
     void allocationPointAdjusted(int heapIndex);
     void promptlyFreed(size_t gcInfoIndex);
 
+#if ENABLE(ASSERT)
+    static void incrementSelfKeepAliveAllocations();
+    static void decrementSelfKeepAliveAllocations();
+#endif
+
 private:
     enum SnapshotType {
         HeapSnapshot,
@@ -728,6 +733,9 @@ private:
     static uintptr_t s_mainThreadStackStart;
     static uintptr_t s_mainThreadUnderestimatedStackSize;
     static SafePointBarrier* s_safePointBarrier;
+#if ENABLE(ASSERT)
+    static int s_selfKeepAliveAllocationsOnMainThread;
+#endif
 
     // We can't create a static member of type ThreadState here
     // because it will introduce global constructor and destructor.