It’s a new Silk Road. Asian products have long headed west, but U.S.-based app and console game makers have only recently started adapting their products to sell overseas. China’s 366 million mobile gamers — more than the entire U.S. population — are in particularly high demand. Localization is a costly process that sometimes backfires, but when it succeeds, it offers a bonanza for developers. It’s giving rise to firms like Boston-based Oniix Mobile, which helps with translation, distribution patterns and more, so that in the digital arena, at least, East and West can meet.