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

third_party/WebKit/Source/core/css/CSSValuePool.cpp

 /*
  * Copyright (C) 2011, 2012 Apple 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 16 matching lines @@
 
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/style/ComputedStyle.h"
 #include "wtf/Threading.h"
 
 namespace blink {
 
 CSSValuePool& cssValuePool()
 {
-    DEFINE_STATIC_LOCAL(Persistent<CSSValuePool>, pool, (new CSSValuePool()));
-    return *pool;
+    DEFINE_STATIC_LOCAL(CSSValuePool, pool, (new CSSValuePool));
+    return pool;
 }
 
 CSSValuePool::CSSValuePool()
     : m_inheritedValue(CSSInheritedValue::create())
     , m_implicitInitialValue(CSSInitialValue::createImplicit())
     , m_explicitInitialValue(CSSInitialValue::createExplicit())
     , m_unsetValue(CSSUnsetValue::create())
     , m_colorTransparent(CSSColorValue::create(Color::transparent))
     , m_colorWhite(CSSColorValue::create(Color::white))
     , m_colorBlack(CSSColorValue::create(Color::black))
@@ skipping 127 matching lines @@
     visitor->trace(m_colorBlack);
     visitor->trace(m_pixelValueCache);
     visitor->trace(m_percentValueCache);
     visitor->trace(m_numberValueCache);
     visitor->trace(m_fontFaceValueCache);
     visitor->trace(m_fontFamilyValueCache);
 #endif
 }
 
 } // namespace blink