Begin tracking why layout is invalidated

Source/core/svg/SVGMaskElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. 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
@@ skipping 129 matching lines @@
 }
 
 void SVGMaskElement::childrenChanged(const ChildrenChange& change)
 {
     SVGElement::childrenChanged(change);
 
     if (change.byParser)
         return;
 
     if (LayoutObject* object = layoutObject())
-        object->setNeedsLayoutAndFullPaintInvalidation();
+        object->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::ChildChanged);
 }
 
 LayoutObject* SVGMaskElement::createLayoutObject(const ComputedStyle&)
 {
     return new LayoutSVGResourceMasker(this);
 }
 
 bool SVGMaskElement::selfHasRelativeLengths() const
 {
     return m_x->currentValue()->isRelative()
         || m_y->currentValue()->isRelative()
         || m_width->currentValue()->isRelative()
         || m_height->currentValue()->isRelative();
 }
 
 } // namespace blink