Oilpan: |SVGViewSpec::m_contextElement| should be a member.

Source/core/svg/SVGViewSpec.cpp

Index: Source/core/svg/SVGViewSpec.cpp
diff --git a/Source/core/svg/SVGViewSpec.cpp b/Source/core/svg/SVGViewSpec.cpp
index 24c82b4fe41c0c30b3c88830cac5134bbcaa702a..6bb831af0b4db17a47a1fec29a0ee75aa2fb20c1 100644
--- a/Source/core/svg/SVGViewSpec.cpp
+++ b/Source/core/svg/SVGViewSpec.cpp
@@ -214,13 +214,7 @@ bool SVGViewSpec::parseViewSpecInternal(const CharType* ptr, const CharType* end
 
 void SVGViewSpec::trace(Visitor* visitor)
 {
-    visitor->registerWeakMembers<SVGViewSpec, &SVGViewSpec::clearWeakMembers>(this);
-}
-
-void SVGViewSpec::clearWeakMembers(Visitor* visitor)
-{
-    if (!visitor->isAlive(m_contextElement))
-        detachContextElement();
+    visitor->trace(m_contextElement);
 }
 
 }