Oilpan: Prepare to move SQLResultSet and SQLResultSetRowList to oilpan heap.

Source/modules/webdatabase/SQLStatementBackend.h

 /*
  * Copyright (C) 2007, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 40 matching lines @@
     bool execute(DatabaseBackend*);
     bool lastExecutionFailedDueToQuota() const;
 
     bool hasStatementCallback() const { return m_hasCallback; }
     bool hasStatementErrorCallback() const { return m_hasErrorCallback; }
 
     void setVersionMismatchedError(DatabaseBackend*);
 
     AbstractSQLStatement* frontend();
     virtual PassRefPtr<SQLError> sqlError() const OVERRIDE;
-    virtual PassRefPtr<SQLResultSet> sqlResultSet() const OVERRIDE;
+    virtual SQLResultSet* sqlResultSet() const OVERRIDE;
 
 private:
     SQLStatementBackend(PassOwnPtr<AbstractSQLStatement>, const String& statement,
         const Vector<SQLValue>& arguments, int permissions);
 
     void setFailureDueToQuota(DatabaseBackend*);
     void clearFailureDueToQuota();
 
     OwnPtr<AbstractSQLStatement> m_frontend;
     String m_statement;
     Vector<SQLValue> m_arguments;
     bool m_hasCallback;
     bool m_hasErrorCallback;
 
     RefPtr<SQLError> m_error;
-    RefPtr<SQLResultSet> m_resultSet;
+    RefPtrWillBeMember<SQLResultSet> m_resultSet;
 
     int m_permissions;
 };
 
 } // namespace WebCore
 
 #endif // SQLStatementBackend_h