Implement SetWrapperReferenceTo idl attribute within traceWrappers for svg elements

third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h

Index: third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h
diff --git a/third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h b/third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h
index bbbb40cab964c5ee2eaf0ca54fed5014b2a9c25d..bbd3da2c7d3eea52149b3e5170a0651351ea3528 100644
--- a/third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h
+++ b/third_party/WebKit/Source/core/svg/SVGAnimatedLengthList.h
@@ -46,6 +46,11 @@ public:
         return new SVGAnimatedLengthList(contextElement, attributeName, initialValue);
     }
 
+    DEFINE_INLINE_VIRTUAL_TRACE_WRAPPERS()
+    {
+        visitor->traceWrappers(contextElement());
+    }
+
 protected:
     SVGAnimatedLengthList(SVGElement* contextElement, const QualifiedName& attributeName, SVGLengthList* initialValue)
         : SVGAnimatedProperty<SVGLengthList>(contextElement, attributeName, initialValue) { }