# File lib/selenium/webdriver/firefox/profile.rb, line 72
        def layout_on_disk
          profile_dir = @model ? create_tmp_copy(@model) : Dir.mktmpdir("webdriver-profile")
          FileReaper << profile_dir

          install_extensions(profile_dir)
          delete_lock_files(profile_dir)
          delete_extensions_cache(profile_dir)
          update_user_prefs_in(profile_dir)

          profile_dir
        end