Put debugging assertions into sql::Statement.

sql/meta_table.h

 // 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.
 
 #ifndef SQL_META_TABLE_H_
 #define SQL_META_TABLE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 53 matching lines @@
 
   // Retrieves the value associated with the given key. This will use sqlite's
   // type conversion rules. It will return true on success.
   bool GetValue(const char* key, std::string* value);
   bool GetValue(const char* key, int* value);
   bool GetValue(const char* key, int64* value);
 
  private:
   // Conveniences to prepare the two types of statements used by
   // MetaTableHelper.
-  bool PrepareSetStatement(Statement* statement, const char* key);
+  void PrepareSetStatement(Statement* statement, const char* key);
   bool PrepareGetStatement(Statement* statement, const char* key);
 
   Connection* db_;
 
   DISALLOW_COPY_AND_ASSIGN(MetaTable);
 };
 
 }  // namespace sql
 
 #endif  // SQL_META_TABLE_H_