Clear statement before closing db in cookie code.

sql/statement.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sql/statement.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/sqlite/sqlite3.h"
 
@@ skipping 17 matching lines @@
   // one statement active for a given sqlite3_stmt at any time, so this won't
   // mess with anything.
   Reset();
 }
 
 void Statement::Assign(scoped_refptr<Connection::StatementRef> ref) {
   Reset();
   ref_ = ref;
 }
 
+void Statement::Clear() {
+  Assign(new Connection::StatementRef);
+  succeeded_ = false;
+}
+
 bool Statement::CheckValid() const {
   if (!is_valid())
     DLOG(FATAL) << "Cannot call mutating statements on an invalid statement.";
   return is_valid();
 }
 
 bool Statement::Run() {
   if (!CheckValid())
     return false;
 
@@ skipping 218 matching lines @@
 
 int Statement::CheckError(int err) {
   // Please don't add DCHECKs here, OnSqliteError() already has them.
   succeeded_ = (err == SQLITE_OK || err == SQLITE_ROW || err == SQLITE_DONE);
   if (!succeeded_ && is_valid())
     return ref_->connection()->OnSqliteError(err, this);
   return err;
 }
 
 }  // namespace sql