chrome最近版本有个“m”，代表什么?

  // Return a human readable modifier for the version string, e.g.
  // the channel (dev, beta, stable). Returns true if this operation succeeded,
  // on success, channel contains one of "", "unknown", "dev" or "beta" (unless
  // it is a multi-install product, in which case it will return "m",
  // "unknown-m", "dev-m", or "beta-m").
  static bool GetChromeChannelAndModifiers(bool system_install,
                                           base::string16* channel);