[SVG Fonts] Fix <font-face> element leak document

Source/core/svg/SVGFontFaceElement.cpp

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 32 matching lines @@
 #include "platform/fonts/Font.h"
 
 namespace WebCore {
 
 using namespace SVGNames;
 
 inline SVGFontFaceElement::SVGFontFaceElement(Document& document)
     : SVGElement(font_faceTag, document)
     , m_fontFaceRule(StyleRuleFontFace::create())
     , m_fontElement(0)
+    , m_weakFactory(this)
 {
     ScriptWrappable::init(this);
     RefPtrWillBeRawPtr<MutableStylePropertySet> styleDeclaration = MutableStylePropertySet::create(HTMLStandardMode);
     m_fontFaceRule->setProperties(styleDeclaration.release());
 }
 
 PassRefPtr<SVGFontFaceElement> SVGFontFaceElement::create(Document& document)
 {
     return adoptRef(new SVGFontFaceElement(document));
 }
@@ skipping 284 matching lines @@
 
 void SVGFontFaceElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     SVGElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
     rebuildFontFace();
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG_FONTS)