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

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 106 matching lines @@
         return;
     }
     if (state == ParseHeight && i > start) {
         int height = charactersToInt(value + start, i - start);
         iconSizes.append(IntSize(width, height));
     }
 }
 
 static LinkEventSender& linkLoadEventSender()
 {
-    DEFINE_STATIC_LOCAL(Persistent<LinkEventSender>, sharedLoadEventSender, (LinkEventSender::create(EventTypeNames::load)));
-    return *sharedLoadEventSender;
+    DEFINE_STATIC_LOCAL(LinkEventSender, sharedLoadEventSender, (LinkEventSender::create(EventTypeNames::load)));
+    return sharedLoadEventSender;
 }
 
 static bool styleSheetTypeIsSupported(const String& type)
 {
     String trimmedType = ContentType(type).type();
     return trimmedType.isEmpty() || MIMETypeRegistry::isSupportedStyleSheetMIMEType(trimmedType);
 }
 
 void HTMLLinkElement::parseSizesAttribute(const AtomicString& value, Vector<IntSize>& iconSizes)
 {
@@ skipping 654 matching lines @@
 }
 
 DEFINE_TRACE(LinkStyle)
 {
     visitor->trace(m_sheet);
     LinkResource::trace(visitor);
     ResourceOwner<StyleSheetResource>::trace(visitor);
 }
 
 } // namespace blink