Oilpan: Prepare to move AbstractSQLStatementBackend and SQLStatementBackend 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 26 matching lines @@
 
 namespace WebCore {
 
 class AbstractSQLStatement;
 class DatabaseBackend;
 class SQLError;
 class SQLTransactionBackend;
 
 class SQLStatementBackend FINAL : public AbstractSQLStatementBackend {
 public:
-    static PassRefPtr<SQLStatementBackend> create(PassOwnPtr<AbstractSQLStatement>,
+    static PassRefPtrWillBeRawPtr<SQLStatementBackend> create(PassOwnPtr<AbstractSQLStatement>,
         const String& sqlStatement, const Vector<SQLValue>& arguments, int permissions);
+    virtual void trace(Visitor*) OVERRIDE;
 
     bool execute(DatabaseBackend*);
     bool lastExecutionFailedDueToQuota() const;
 
     bool hasStatementCallback() const { return m_hasCallback; }
     bool hasStatementErrorCallback() const { return m_hasErrorCallback; }
 
     void setVersionMismatchedError(DatabaseBackend*);
 
     AbstractSQLStatement* frontend();
@@ skipping 15 matching lines @@
 
     RefPtr<SQLError> m_error;
     RefPtr<SQLResultSet> m_resultSet;
 
     int m_permissions;
 };
 
 } // namespace WebCore
 
 #endif // SQLStatementBackend_h