[CSS Regions] Elements in a region should be assignable to a named flow

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 439 matching lines @@
         const EventListenerVector& entry = element->getEventListeners(eventNames().loadEvent);
         for (size_t i = 0; i < entry.size(); ++i) {
             if (entry[i].useCapture)
                 return true;
         }
     }
 
     return false;
 }
 
+bool SVGElement::moveToFlowThreadIsNeeded(RefPtr<RenderStyle>& cachedStyle)
+{
+    // Allow only svg root elements to be directly collected by a render flow thread.
+    return parentNode() && !parentNode()->isSVGElement() && hasTagName(SVGNames::svgTag) && Element::moveToFlowThreadIsNeeded(cachedStyle);
+}
+
 void SVGElement::sendSVGLoadEventIfPossible(bool sendParentLoadEvents)
 {
     RefPtr<SVGElement> currentTarget = this;
     while (currentTarget && currentTarget->haveLoadedRequiredResources()) {
         RefPtr<Element> parent;
         if (sendParentLoadEvents)
             parent = currentTarget->parentOrShadowHostElement(); // save the next parent to dispatch too incase dispatching the event changes the tree
         if (hasLoadListener(currentTarget.get()))
             currentTarget->dispatchEvent(Event::create(eventNames().loadEvent, false, false));
         currentTarget = (parent && parent->isSVGElement()) ? static_pointer_cast<SVGElement>(parent) : RefPtr<SVGElement>();
@@ skipping 265 matching lines @@
     if (name == classAttr)
         return isSVGStyledElement();
 
     return animatableAttributes.contains(name);
 }
 #endif
 
 }
 
 #endif // ENABLE(SVG)