Improve DEFINE_STATIC_LOCAL()'s handling of Blink GCed objects.

third_party/WebKit/Source/core/html/HTMLDetailsElement.cpp

 /*
  * Copyright (C) 2010, 2011 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 55 matching lines @@
     {
         HTMLContentSelectFilter::trace(visitor);
     }
 
 private:
     FirstSummarySelectFilter() { }
 };
 
 static DetailsEventSender& detailsToggleEventSender()
 {
-    DEFINE_STATIC_LOCAL(Persistent<DetailsEventSender>, sharedToggleEventSender, (DetailsEventSender::create(EventTypeNames::toggle)));
-    return *sharedToggleEventSender;
+    DEFINE_STATIC_LOCAL(DetailsEventSender, sharedToggleEventSender, (DetailsEventSender::create(EventTypeNames::toggle)));
+    return sharedToggleEventSender;
 }
 
 RawPtr<HTMLDetailsElement> HTMLDetailsElement::create(Document& document)
 {
     RawPtr<HTMLDetailsElement> details = new HTMLDetailsElement(document);
     details->ensureUserAgentShadowRoot();
     return details.release();
 }
 
 HTMLDetailsElement::HTMLDetailsElement(Document& document)
@@ skipping 86 matching lines @@
 {
     setAttribute(openAttr, m_isOpen ? nullAtom : emptyAtom);
 }
 
 bool HTMLDetailsElement::isInteractiveContent() const
 {
     return true;
 }
 
 } // namespace blink