def _copy_webkit_test_files(self):
        _log.debug('Copying WebKit resources files')
        for f in self._resources_files_to_copy:
            webkit_filename = self._filesystem.join(self._layout_root, "resources", f)
            if self._filesystem.isfile(webkit_filename):
                self._filesystem.copyfile(webkit_filename, self._filesystem.join(self._doc_root, "resources", f))
        _log.debug('Copying WebKit web platform server config.json')
        config_wk_filename = self._filesystem.join(self._layout_root, "imported", "w3c", "resources", "config.json")
        if self._filesystem.isfile(config_wk_filename):
            config_json = self._filesystem.read_text_file(config_wk_filename).replace("%CERTS_DIR%", self._filesystem.join(self._output_dir, "_wpt_certs"))
            self._filesystem.write_text_file(self._filesystem.join(self._doc_root, "config.json"), config_json)

        wpt_testharnessjs_file = self._filesystem.join(self._doc_root, "resources", "testharness.js")
        layout_tests_testharnessjs_file = self._filesystem.join(self._layout_root, "resources", "testharness.js")
        # FIXME: Next line to be removed once all bots have wpt_testharnessjs_file updated correctly. See https://bugs.webkit.org/show_bug.cgi?id=152257.
        self._filesystem.copyfile(layout_tests_testharnessjs_file, wpt_testharnessjs_file)
        if (not self._filesystem.compare(wpt_testharnessjs_file, layout_tests_testharnessjs_file)):
            _log.warning("\n//////////\nWPT tests are not using the same testharness.js file as other WebKit Layout tests.\nWebKit testharness.js might need to be updated according WPT testharness.js.\n//////////\n")