def __init__(self, port_obj, name, pidfile=None):
        http_server_base.HttpServerBase.__init__(self, port_obj)
        self._output_dir = port_obj.results_directory()

        self._name = name
        self._log_file_name = '%s_process_log.out.txt' % (self._name)

        self._wsout = None
        self._process = None
        self._pid_file = pidfile
        if not self._pid_file:
            self._pid_file = self._filesystem.join(self._runtime_path, '%s.pid' % self._name)
        self._servers_file = self._filesystem.join(self._runtime_path, '%s_servers.json' % (self._name))

        self._stdout_data = None
        self._stderr_data = None
        self._filesystem = port_obj.host.filesystem
        self._layout_root = port_obj.layout_tests_dir()
        self._doc_root = self._filesystem.join(self._layout_root, doc_root(port_obj))

        self._resources_files_to_copy = ['testharness.css', 'testharnessreport.js']

        current_dir_path = self._filesystem.abspath(self._filesystem.split(__file__)[0])
        self._start_cmd = ["python", self._filesystem.join(current_dir_path, "web_platform_test_launcher.py"), self._servers_file]
        self._doc_root_path = self._filesystem.join(self._layout_root, self._doc_root)