Generalize migration code in WebDatabase.

chrome/browser/webdata/token_service_table.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 "chrome/browser/webdata/token_service_table.h"
 
 #include <map>
 #include <string>
 
 #include "base/logging.h"
 #include "chrome/browser/password_manager/encryptor.h"
 #include "sql/statement.h"
 
 bool TokenServiceTable::Init() {
   if (!db_->DoesTableExist("token_service")) {
     if (!db_->Execute("CREATE TABLE token_service ("
                       "service VARCHAR PRIMARY KEY NOT NULL,"
                       "encrypted_token BLOB)")) {
       NOTREACHED();
       return false;
     }
   }
   return true;
 }
 
 bool TokenServiceTable::IsSyncable() {
   return true;
 }
 
+bool TokenServiceTable::MigrateToVersion(int version,
+                                         const std::string& app_locale,
+                                         bool* update_compatible_version) {
+  return true;
+}
+
 bool TokenServiceTable::RemoveAllTokens() {
   sql::Statement s(db_->GetUniqueStatement(
       "DELETE FROM token_service"));
 
   return s.Run();
 }
 
 bool TokenServiceTable::SetTokenForService(const std::string& service,
                                            const std::string& token) {
   std::string encrypted_token;
@@ skipping 32 matching lines @@
     if (entry_ok) {
       Encryptor::DecryptString(encrypted_token, &decrypted_token);
       (*tokens)[service] = decrypted_token;
     } else {
       NOTREACHED();
       return false;
     }
   }
   return true;
 }