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

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

Index: third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp b/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
index eec5eb4625d4fd4ce95c32121b79cb9a1acc8b7d..0206083aec5460f851ef289eace97eb73169bb8d 100644
--- a/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
@@ -265,7 +265,10 @@ void SVGSVGElement::svgAttributeChanged(const QualifiedName& attrName) {
     // 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(