Generalize migration code in WebDatabase.

chrome/browser/webdata/web_database.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_WEB_DATABASE_H_
 #define CHROME_BROWSER_WEBDATA_WEB_DATABASE_H_
 
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "sql/connection.h"
 #include "sql/init_status.h"
 #include "sql/meta_table.h"
 
 class AutofillTable;
 class KeywordTable;
 class LoginsTable;
 class TokenServiceTable;
 class WebAppsTable;
+class WebDatabaseTable;
 class WebIntentsTable;
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class NotificationService;
 }
 
@@ skipping 32 matching lines @@
 
  private:
   // Used by |Init()| to migration database schema from older versions to
   // current version.  Requires the |app_locale| to be passed as a parameter as
   // the locale can only safely be queried on the UI thread.
   sql::InitStatus MigrateOldVersionsAsNeeded(const std::string& app_locale);
 
   sql::Connection db_;
   sql::MetaTable meta_table_;
 
-  scoped_ptr<AutofillTable> autofill_table_;
-  scoped_ptr<KeywordTable> keyword_table_;
-  scoped_ptr<LoginsTable> logins_table_;
-  scoped_ptr<TokenServiceTable> token_service_table_;
-  scoped_ptr<WebAppsTable> web_apps_table_;
+  // TODO(joi): All of the typed pointers are going in a future
+  // change, as we remove knowledge of the specific types from this
+  // class.
+  AutofillTable* autofill_table_;
+  KeywordTable* keyword_table_;
+  LoginsTable* logins_table_;
+  TokenServiceTable* token_service_table_;
+  WebAppsTable* web_apps_table_;
   // TODO(thakis): Add a migration to delete this table, then remove this.
-  scoped_ptr<WebIntentsTable> web_intents_table_;
+  WebIntentsTable* web_intents_table_;
+
+  // Owns all the different database tables that have been added to
+  // this object.
+  ScopedVector<WebDatabaseTable> tables_;
 
   scoped_ptr<content::NotificationService> notification_service_;
 
   DISALLOW_COPY_AND_ASSIGN(WebDatabase);
 };
 
 #endif  // CHROME_BROWSER_WEBDATA_WEB_DATABASE_H_