Generalize migration code in WebDatabase.

chrome/browser/webdata/web_apps_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/web_apps_table.h"
 
 #include "base/logging.h"
 #include "chrome/browser/history/history_database.h"
 #include "googleurl/src/gurl.h"
 #include "sql/statement.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/codec/png_codec.h"
 
 bool WebAppsTable::Init() {
   return (InitWebAppIconsTable() && InitWebAppsTable());
 }
 
 bool WebAppsTable::IsSyncable() {
   return true;
 }
 
+bool WebAppsTable::MigrateToVersion(int version,
+                                    const std::string& app_locale,
+                                    bool* update_compatible_version) {
+  return true;
+}
+
 bool WebAppsTable::InitWebAppIconsTable() {
   if (!db_->DoesTableExist("web_app_icons")) {
     if (!db_->Execute("CREATE TABLE web_app_icons ("
                       "url LONGVARCHAR,"
                       "width int,"
                       "height int,"
                       "image BLOB, UNIQUE (url, width, height))")) {
       NOTREACHED();
       return false;
     }
@@ skipping 81 matching lines @@
 
   if (!delete_s.Run())
     return false;
 
   sql::Statement delete_s2(db_->GetUniqueStatement(
       "DELETE FROM web_apps WHERE url = ?"));
   delete_s2.BindString(0, history::HistoryDatabase::GURLToDatabaseURL(url));
 
   return delete_s2.Run();
 }