# File lib/chromedriver/helper.rb, line 98
    def platform
      cfg = RbConfig::CONFIG
      host_cpu = cfg["host_cpu"]
      host_os = cfg["host_os"]

      case host_os
      when /linux/ then
        host_cpu =~ /x86_64|amd64/ ? "linux64" : "linux32"
      when /darwin/ then "mac"
      when /mswin/ then "win"
      when /mingw/ then "win"
      else
        raise("Unsupported host OS '#{host_os}'")
      end
    end