Well, the manifest would not be changed except updating the application, the purpose of this patch is to update the WidgetInfo when system locale has been changed. We do can use  WidgetHandler::Parse to update the information, but there are two problems:
1. Many other unneeded items will be updated  except the i18n related items.
2. According to current manifest handler mechanism, it's hard to invoke WidgetHandler::Parse alone, all other manifest handlers would be executed as well.