Generalize migration code in WebDatabase.

chrome/browser/webdata/logins_table.h

 // Copyright (c) 2012 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 CHROME_BROWSER_WEBDATA_LOGINS_TABLE_H_
 #define CHROME_BROWSER_WEBDATA_LOGINS_TABLE_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/webdata/web_database_table.h"
 
 #if defined(OS_WIN)
 struct IE7PasswordInfo;
 #endif
 
 // This class manages the logins table within the SQLite database passed to the
 // constructor. We no longer store passwords here except for imported IE
 // passwords, so this class is now mostly responsible for deleting the table if
 // it is found to exist. (The data was migrated out long ago.)
 class LoginsTable : public WebDatabaseTable {
  public:
   LoginsTable(sql::Connection* db, sql::MetaTable* meta_table)
       : WebDatabaseTable(db, meta_table) {}
   virtual ~LoginsTable() {}
   virtual bool Init() OVERRIDE;
   virtual bool IsSyncable() OVERRIDE;
+  virtual bool MigrateToVersion(int version,
+                                const std::string& app_locale,
+                                bool* update_compatible_version) OVERRIDE;
 
 #if defined(OS_WIN)
   // Adds |info| to the list of imported passwords from ie7/ie8.
   bool AddIE7Login(const IE7PasswordInfo& info);
 
   // Removes |info| from the list of imported passwords from ie7/ie8.
   bool RemoveIE7Login(const IE7PasswordInfo& info);
 
   // Return the ie7/ie8 login matching |info|.
   bool GetIE7Login(const IE7PasswordInfo& info, IE7PasswordInfo* result);
 #endif
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LoginsTable);
 };
 
 #endif  // CHROME_BROWSER_WEBDATA_LOGINS_TABLE_H_