[Oilpan]: Move StyleMedia to the oilpan heap using transition types.

Source/core/css/StyleMedia.h

Index: Source/core/css/StyleMedia.h
diff --git a/Source/core/css/StyleMedia.h b/Source/core/css/StyleMedia.h
index fb83c427185f0305133f0e5da7aa2c255275a887..5ff83865abd7cf37e3085435313b5dd8d8f82f79 100644
--- a/Source/core/css/StyleMedia.h
+++ b/Source/core/css/StyleMedia.h
@@ -28,6 +28,7 @@
 #define StyleMedia_h
 
 #include "core/frame/DOMWindowProperty.h"
+#include "heap/Handle.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
@@ -35,13 +36,15 @@ namespace WebCore {
 
 class LocalFrame;
 
-class StyleMedia : public RefCounted<StyleMedia>, public DOMWindowProperty {
+class StyleMedia : public RefCountedWillBeGarbageCollectedFinalized<StyleMedia>, public DOMWindowProperty {
 public:
-    static PassRefPtr<StyleMedia> create(LocalFrame* frame) { return adoptRef(new StyleMedia(frame));}
+    static PassRefPtrWillBeRawPtr<StyleMedia> create(LocalFrame* frame) { return adoptRefWillBeNoop(new StyleMedia(frame));}
 
     AtomicString type() const;
     bool matchMedium(const String&) const;
 
+    void trace(Visitor*) { }
+
 private:
     explicit StyleMedia(LocalFrame*);
 };