Ignored title in shadow should cause StyleSheet.title = null.

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

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2006 Apple Inc. All rights reserved.
  * 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 82 matching lines @@
 }
 
 void SVGStyleElement::setTitle(const AtomicString& title)
 {
     setAttribute(SVGNames::titleAttr, title);
 }
 
 void SVGStyleElement::parseAttribute(const QualifiedName& name, const AtomicString& oldValue, const AtomicString& value)
 {
     if (name == SVGNames::titleAttr) {
-        if (m_sheet)
+        if (m_sheet && isInDocumentTree())
             m_sheet->setTitle(value);
 
         return;
     }
 
     SVGElement::parseAttribute(name, oldValue, value);
 }
 
 void SVGStyleElement::finishParsingChildren()
 {
@@ skipping 41 matching lines @@
     dispatchEvent(Event::create(EventTypeNames::error));
 }
 
 DEFINE_TRACE(SVGStyleElement)
 {
     StyleElement::trace(visitor);
     SVGElement::trace(visitor);
 }
 
 } // namespace blink