Oilpan: move SVG property hierarchy to the heap.

Source/core/svg/SVGPatternElement.h

Index: Source/core/svg/SVGPatternElement.h
diff --git a/Source/core/svg/SVGPatternElement.h b/Source/core/svg/SVGPatternElement.h
index ed2615d347b8fee3d5767e81dac514abc00c4d9f..895cad1d0df904c6a2f7b20fd7c834183dcfe2a0 100644
--- a/Source/core/svg/SVGPatternElement.h
+++ b/Source/core/svg/SVGPatternElement.h
@@ -31,16 +31,18 @@
 #include "core/svg/SVGTests.h"
 #include "core/svg/SVGURIReference.h"
 #include "core/svg/SVGUnitTypes.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
-struct PatternAttributes;
+class PatternAttributes;
 
 class SVGPatternElement final : public SVGElement,
                                 public SVGURIReference,
                                 public SVGTests,
                                 public SVGFitToViewBox {
     DEFINE_WRAPPERTYPEINFO();
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SVGPatternElement);
 public:
     DECLARE_NODE_FACTORY(SVGPatternElement);
 
@@ -59,6 +61,8 @@ public:
     const SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType>* patternUnits() const { return m_patternUnits.get(); }
     const SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType>* patternContentUnits() const { return m_patternContentUnits.get(); }
 
+    virtual void trace(Visitor*) override;
+
 private:
     explicit SVGPatternElement(Document&);
 
@@ -74,13 +78,13 @@ private:
 
     virtual bool selfHasRelativeLengths() const override;
 
-    RefPtr<SVGAnimatedLength> m_x;
-    RefPtr<SVGAnimatedLength> m_y;
-    RefPtr<SVGAnimatedLength> m_width;
-    RefPtr<SVGAnimatedLength> m_height;
-    RefPtr<SVGAnimatedTransformList> m_patternTransform;
-    RefPtr<SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType> > m_patternUnits;
-    RefPtr<SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType> > m_patternContentUnits;
+    RefPtrWillBeMember<SVGAnimatedLength> m_x;
+    RefPtrWillBeMember<SVGAnimatedLength> m_y;
+    RefPtrWillBeMember<SVGAnimatedLength> m_width;
+    RefPtrWillBeMember<SVGAnimatedLength> m_height;
+    RefPtrWillBeMember<SVGAnimatedTransformList> m_patternTransform;
+    RefPtrWillBeMember<SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType> > m_patternUnits;
+    RefPtrWillBeMember<SVGAnimatedEnumeration<SVGUnitTypes::SVGUnitType> > m_patternContentUnits;
 };
 
 } // namespace blink