Oilpan: move SVG property hierarchy to the heap.

Source/core/svg/SVGPathSegListSource.h

Index: Source/core/svg/SVGPathSegListSource.h
diff --git a/Source/core/svg/SVGPathSegListSource.h b/Source/core/svg/SVGPathSegListSource.h
index 0fb6492697fa9164e59f9a2cc6d59af11a874c1a..6935ea417b326d5ea5418fdaa4b1ef6e89e6d38a 100644
--- a/Source/core/svg/SVGPathSegListSource.h
+++ b/Source/core/svg/SVGPathSegListSource.h
@@ -24,6 +24,7 @@
 #include "core/svg/SVGPathSegList.h"
 #include "core/svg/SVGPathSource.h"
 #include "platform/geometry/FloatPoint.h"
+#include "platform/heap/Handle.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 
@@ -33,6 +34,8 @@ class SVGPathSegListSource final : public SVGPathSource {
 public:
     SVGPathSegListSource(SVGPathSegList::ConstIterator, SVGPathSegList::ConstIterator);
 
+    virtual void trace(Visitor*) override;
+
 private:
     virtual bool hasMoreData() const override;
     virtual bool moveToNextToken() override { return true; }
@@ -49,7 +52,7 @@ private:
     virtual bool parseCurveToQuadraticSmoothSegment(FloatPoint&) override;
     virtual bool parseArcToSegment(float&, float&, float&, bool&, bool&, FloatPoint&) override;
 
-    RefPtr<SVGPathSeg> m_segment;
+    RefPtrWillBeMember<SVGPathSeg> m_segment;
     SVGPathSegList::ConstIterator m_itCurrent;
     SVGPathSegList::ConstIterator m_itEnd;
 };