Dirty pres. attribute style on <svg> dimension change when not attached

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

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google, Inc.
  *
  * 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 247 matching lines @@
       attrName == SVGNames::yAttr) {
     updateRelativeLengthsOrViewBox = true;
     updateRelativeLengthsInformation();
     invalidateRelativeLengthClients();
 
     // At the SVG/HTML boundary (aka LayoutSVGRoot), the width and
     // height attributes can affect the replaced size so we need
     // to mark it for updating.
     if (widthOrHeightChanged) {
       LayoutObject* layoutObject = this->layoutObject();
-      if (layoutObject && layoutObject->isSVGRoot()) {
+      // If the element is not attached, we cannot be sure if it is (going to
+      // be) an outermost root, so always mark presentation attributes dirty in
+      // that case.
+      if (!layoutObject || layoutObject->isSVGRoot()) {
         invalidateSVGPresentationAttributeStyle();
         setNeedsStyleRecalc(LocalStyleChange,
                             StyleChangeReasonForTracing::create(
                                 StyleChangeReason::SVGContainerSizeChange));
       }
     } else {
       invalidateSVGPresentationAttributeStyle();
       setNeedsStyleRecalc(LocalStyleChange,
                           StyleChangeReasonForTracing::fromAttribute(attrName));
     }
@@ skipping 445 matching lines @@
   visitor->trace(m_width);
   visitor->trace(m_height);
   visitor->trace(m_translation);
   visitor->trace(m_timeContainer);
   visitor->trace(m_viewSpec);
   SVGGraphicsElement::trace(visitor);
   SVGFitToViewBox::trace(visitor);
 }
 
 }  // namespace blink