Avoid race-warning for access to animatableAttributes

third_party/WebKit/Source/core/svg/SVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * 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
@@ skipping 31 matching lines @@
 #include "core/layout/svg/LayoutSVGResourceContainer.h"
 #include "core/svg/SVGCursorElement.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGElementRareData.h"
 #include "core/svg/SVGGraphicsElement.h"
 #include "core/svg/SVGSVGElement.h"
 #include "core/svg/SVGTitleElement.h"
 #include "core/svg/SVGUseElement.h"
 #include "platform/JSONValues.h"
 #include "wtf/TemporaryChange.h"
+#include "wtf/Threading.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 using namespace SVGNames;
 
 SVGElement::SVGElement(const QualifiedName& tagName, Document& document, ConstructionType constructionType)
     : Element(tagName, &document, constructionType)
 #if ENABLE(ASSERT)
     , m_inRelativeLengthClientsInvalidation(false)
@@ skipping 912 matching lines @@
 
 SVGElement::InstanceUpdateBlocker::~InstanceUpdateBlocker()
 {
     if (m_targetElement)
         m_targetElement->setInstanceUpdatesBlocked(false);
 }
 
 #if ENABLE(ASSERT)
 bool SVGElement::isAnimatableAttribute(const QualifiedName& name) const
 {
-    DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, animatableAttributes, ());
+    // This static is atomically initialized to dodge a warning about
+    // a race when dumping debug data for a layer.
+    AtomicallyInitializedStaticReference(HashSet<QualifiedName>, animatableAttributes, new HashSet<QualifiedName>());
 
     if (animatableAttributes.isEmpty()) {
         const QualifiedName* const animatableAttrs[] = {
             &XLinkNames::hrefAttr,
             &SVGNames::amplitudeAttr,
             &SVGNames::azimuthAttr,
             &SVGNames::baseFrequencyAttr,
             &SVGNames::biasAttr,
             &SVGNames::clipPathUnitsAttr,
             &SVGNames::cxAttr,
@@ skipping 164 matching lines @@
     Element::trace(visitor);
 }
 
 const AtomicString& SVGElement::eventParameterName()
 {
     DEFINE_STATIC_LOCAL(const AtomicString, evtString, ("evt", AtomicString::ConstructFromLiteral));
     return evtString;
 }
 
 } // namespace blink