In run-webkit-tests, start xvfb if necessary.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
 # Copyright (C) 2010 Gabor Rapcsanyi (rgabor@inf.u-szeged.hu), University of Szeged
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 314 matching lines @@
         self._delete_dirs(results_directories[:-self.ARCHIVED_RESULTS_LIMIT])
 
     def _set_up_run(self, test_names):
         self._printer.write_update("Checking build ...")
         if self._options.build:
             exit_code = self._port.check_build(self._needs_servers(test_names), self._printer)
             if exit_code:
                 _log.error("Build check failed")
                 return exit_code
 
+        self._port.setup_test_run()

[qyearsley, 2017/04/14 18:25:40]

I moved this line here so that it happens before the system dependency check on
linux, and so that starting xvfb can be done in Port.setup_test_run, which
seemed like the most obvious place to do it. But, this might change behavior.

The alternatives would be:
 - Add a separate _start_xvfb_if_necessary and call it here, and keep
setup_test_run down below.
 - In the linux port, make check_sys_deps responsible for starting xvfb if
necessary.

[Dirk Pranke, 2017/04/14 21:44:08]

I think moving the order of the calls is fine, but you should move everything
before check_sys_deps(), i.e., call that last in the function so that everything
else is ready as much as possible.

[qyearsley, 2017/04/18 17:58:35]

Done.

+
         # Check that the system dependencies (themes, fonts, ...) are correct.
         if not self._options.nocheck_sys_deps:
             self._printer.write_update("Checking system dependencies ...")
             exit_code = self._port.check_sys_deps(self._needs_servers(test_names))
             if exit_code:
                 return exit_code
 
         if self._options.clobber_old_results:
             self._clobber_old_results()
         elif self._filesystem.exists(self._results_directory):
             self._limit_archived_results_count()
             # Rename the existing results folder for archiving.
             self._rename_results_folder()
 
         # Create the output directory if it doesn't already exist.
         self._port.host.filesystem.maybe_make_directory(self._results_directory)
 
-        self._port.setup_test_run()
         return exit_codes.OK_EXIT_STATUS
 
     def _run_tests(self, tests_to_run, tests_to_skip, repeat_each, iterations,
                    num_workers, retry_attempt=0):
 
         test_inputs = []
         for _ in xrange(iterations):
             for test in tests_to_run:
                 for _ in xrange(repeat_each):
                     test_inputs.append(self._test_input_for_file(test))
@@ skipping 186 matching lines @@
 
         stats = {}
         for result in initial_results.results_by_name.values():
             if result.type != test_expectations.SKIP:
                 stats[result.test_name] = {'results': (_worker_number(result.worker_name), result.test_number, result.pid, int(
                     result.test_run_time * 1000), int(result.total_run_time * 1000))}
         stats_trie = {}
         for name, value in stats.iteritems():
             json_results_generator.add_path_to_trie(name, value, stats_trie)
         return stats_trie