Revert of Remove ineffective PendingScript prefinalizer (2nd attempt.)

third_party/WebKit/Source/core/dom/PendingScript.cpp

 /*
  * Copyright (C) 2010 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 29 matching lines @@
 }
 
 PendingScript::PendingScript(Element* element, ScriptResource* resource)
     : m_watchingForLoad(false)
     , m_element(element)
     , m_integrityFailure(false)
     , m_parserBlockingLoadStartTime(0)
     , m_client(nullptr)
 {
     setScriptResource(resource);
+    ThreadState::current()->registerPreFinalizer(this);
 }
 
 PendingScript::~PendingScript()
 {
-    // Verify explicit dispose().
-    CHECK(!m_client && !m_element && !m_streamer);
 }
 
 void PendingScript::dispose()
 {
     if (!m_client)
         return;
     stopWatchingForLoad();
     releaseElementAndClear();
 }
 
@@ skipping 156 matching lines @@
 bool PendingScript::errorOccurred() const
 {
     if (resource())
         return resource()->errorOccurred();
     if (m_streamer && m_streamer->resource())
         return m_streamer->resource()->errorOccurred();
     return false;
 }
 
 } // namespace blink