Oilpan: Prepare to move FormSubmission to Oilpan heap.

Source/core/loader/FormSubmission.h

Index: Source/core/loader/FormSubmission.h
diff --git a/Source/core/loader/FormSubmission.h b/Source/core/loader/FormSubmission.h
index 35b5530dc61294a3eeeb6855586f296ef4e82a02..b57c7320d7b280c5ee323025a8448e6bd6dbb8b3 100644
--- a/Source/core/loader/FormSubmission.h
+++ b/Source/core/loader/FormSubmission.h
@@ -48,7 +48,7 @@ class FormData;
 struct FrameLoadRequest;
 class HTMLFormElement;
 
-class FormSubmission : public RefCounted<FormSubmission> {
+class FormSubmission : public RefCountedWillBeGarbageCollectedFinalized<FormSubmission> {
 public:
     enum Method { GetMethod, PostMethod, DialogMethod };
 
@@ -93,7 +93,8 @@ public:
         String m_acceptCharset;
     };
 
-    static PassRefPtr<FormSubmission> create(HTMLFormElement*, const Attributes&, PassRefPtrWillBeRawPtr<Event>, FormSubmissionTrigger);
+    static PassRefPtrWillBeRawPtr<FormSubmission> create(HTMLFormElement*, const Attributes&, PassRefPtrWillBeRawPtr<Event>, FormSubmissionTrigger);
+    void trace(Visitor*);
 
     void populateFrameLoadRequest(FrameLoadRequest&);
 
@@ -122,10 +123,10 @@ private:
     KURL m_action;
     AtomicString m_target;
     AtomicString m_contentType;
-    RefPtrWillBePersistent<FormState> m_formState;
+    RefPtrWillBeMember<FormState> m_formState;
     RefPtr<FormData> m_formData;
     String m_boundary;
-    RefPtrWillBePersistent<Event> m_event;
+    RefPtrWillBeMember<Event> m_event;
     Referrer m_referrer;
     String m_origin;
     String m_result;