Have ElementTraversal::firstWithin() take a reference

Source/core/svg/SVGElement.cpp

Index: Source/core/svg/SVGElement.cpp
diff --git a/Source/core/svg/SVGElement.cpp b/Source/core/svg/SVGElement.cpp
index 2f4fe2c5bde1464e0c6ea6b5ac7b3d43760ffbe9..2a40f44fb55c6e2147a0ddd755e8e17460a109ce 100644
--- a/Source/core/svg/SVGElement.cpp
+++ b/Source/core/svg/SVGElement.cpp
@@ -263,7 +263,7 @@ String SVGElement::title() const
 
     // If we aren't an instance in a <use> or the <use> title was not found, then find the first
     // <title> child of this element.
-    Element* titleElement = ElementTraversal::firstWithin(this);
+    Element* titleElement = ElementTraversal::firstWithin(*this);
     for (; titleElement; titleElement = ElementTraversal::nextSkippingChildren(titleElement, this)) {
         if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
             break;