Lend LSan a hand and clear out singleton static persistents first.

third_party/WebKit/Source/platform/heap/ThreadState.h

 /*
  * Copyright (C) 2013 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 508 matching lines @@
   void accumulateSweepingTime(double time) {
     m_accumulatedSweepingTime += time;
   }
 
 #if OS(WIN) && COMPILER(MSVC)
   size_t threadStackSize();
 #endif
 
   void freePersistentNode(PersistentNode*);
 
-  using PersistentClearCallback = void (*)(void*);
+  enum ReleasePersistentMode { ClearPersistent, ReleasePersistent };
+  using PersistentClearCallback = void (*)(void*, ReleasePersistentMode);
 
   void registerStaticPersistentNode(PersistentNode*, PersistentClearCallback);
-  void releaseStaticPersistentNodes();
-
 #if defined(LEAK_SANITIZER)
+  void clearStaticPersistentNodes();
   void enterStaticReferenceRegistrationDisabledScope();
   void leaveStaticReferenceRegistrationDisabledScope();
 #endif
+  void releaseStaticPersistentNodes();
+
 
   void resetHeapCounters();
   void increaseAllocatedObjectSize(size_t);
   void decreaseAllocatedObjectSize(size_t);
   void increaseMarkedObjectSize(size_t);
 
   void callThreadShutdownHooks();
 
   v8::Isolate* isolate() const { return m_isolate; }
 
@@ skipping 226 matching lines @@
 class ThreadStateFor<AnyThread> {
   STATIC_ONLY(ThreadStateFor);
 
  public:
   static ThreadState* state() { return ThreadState::current(); }
 };
 
 }  // namespace blink
 
 #endif  // ThreadState_h