Oilpan: keep FormData on the heap by default.

Source/modules/credentialmanager/LocalCredential.h

Index: Source/modules/credentialmanager/LocalCredential.h
diff --git a/Source/modules/credentialmanager/LocalCredential.h b/Source/modules/credentialmanager/LocalCredential.h
index b7f716ede8df83659efec82877ab8a47544b30bd..cdc1abd2b9deae27a4447f1785b29302dbb4208c 100644
--- a/Source/modules/credentialmanager/LocalCredential.h
+++ b/Source/modules/credentialmanager/LocalCredential.h
@@ -34,7 +34,7 @@ public:
 
     // LocalCredential.idl
     const String& password() const;
-    DOMFormData* formData() const { return m_formData.get(); };
+    DOMFormData* formData() const { return m_formData; };
 
     DECLARE_VIRTUAL_TRACE();
 
@@ -42,8 +42,7 @@ private:
     LocalCredential(WebLocalCredential*);
     LocalCredential(const String& id, const String& password, const String& name, const KURL& avatar);
 
-    // FIXME: Reconsider use of GarbageCollectedFinalized once this can be a Member.
-    RefPtrWillBeMember<DOMFormData> m_formData;
+    Member<DOMFormData> m_formData;
 };
 
 } // namespace blink