Don't unconditionally create a LayoutObject for SVGMarkerElement.

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

Index: third_party/WebKit/Source/core/svg/SVGMarkerElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGMarkerElement.cpp b/third_party/WebKit/Source/core/svg/SVGMarkerElement.cpp
index ff874a564ed4c544ffe50b0a5015d2854b97ca7e..f44a0770c593ed5613b3ce69bf809f9d4e3fec86 100644
--- a/third_party/WebKit/Source/core/svg/SVGMarkerElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGMarkerElement.cpp
@@ -158,4 +158,9 @@ bool SVGMarkerElement::selfHasRelativeLengths() const {
          m_markerHeight->currentValue()->isRelative();
 }
 
+bool SVGMarkerElement::layoutObjectIsNeeded(const ComputedStyle&) {
+  ContainerNode* parent = FlatTreeTraversal::parent(*this);
+  return parent && parent->isSVGElement() && isValid();
+}
+
 }  // namespace blink