Fix all "dangerous-default-value" pylint warnings.

third_party/WebKit/Tools/Scripts/webkitpy/performance_tests/perftestsrunner_unittest.py

 # Copyright (C) 2012 Google Inc. All rights reserved.
 #
 # 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
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 29 matching lines @@
 from webkitpy.layout_tests.port.test import TestPort
 from webkitpy.performance_tests.perftest import ChromiumStylePerfTest
 from webkitpy.performance_tests.perftest import DEFAULT_TEST_RUNNER_COUNT
 from webkitpy.performance_tests.perftest import PerfTest
 from webkitpy.performance_tests.perftestsrunner import PerfTestsRunner
 
 
 class MainTest(unittest.TestCase):
 
     def create_runner(self, args=[]):
+        args = args or []
         options, _ = PerfTestsRunner._parse_args(args)
         test_port = TestPort(host=MockHost(), options=options)
         runner = PerfTestsRunner(args=args, port=test_port)
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'inspector')
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'Bindings')
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'Parser')
         return runner, test_port
 
     def _add_file(self, runner, dirname, filename, content=True):
         dirname = runner._host.filesystem.join(runner._base_path, dirname) if dirname else runner._base_path
@@ skipping 325 matching lines @@
 
 class IntegrationTest(unittest.TestCase):
 
     def _normalize_output(self, log):
         return re.sub(r'(stdev=\s+\d+\.\d{5})\d+', r'\1', re.sub(r'Finished: [0-9\.]+ s', 'Finished: 0.1 s', log))
 
     def _load_output_json(self, runner):
         json_content = runner._host.filesystem.read_text_file(runner._output_json_path())
         return json.loads(re.sub(r'("stdev":\s*\d+\.\d{5})\d+', r'\1', json_content))
 
-    def create_runner(self, args=[], driver_class=TestDriver):
+    def create_runner(self, args=None, driver_class=TestDriver):
+        args = args or []
         options, _ = PerfTestsRunner._parse_args(args)
         test_port = TestPort(host=MockHost(), options=options)
         test_port.create_driver = lambda worker_number=None, no_timeout=False: driver_class()
 
         runner = PerfTestsRunner(args=args, port=test_port)
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'inspector')
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'Bindings')
         runner._host.filesystem.maybe_make_directory(runner._base_path, 'Parser')
 
         return runner, test_port
@@ skipping 151 matching lines @@
     def test_run_with_description(self):
         runner, port = self.create_runner_and_setup_results_template(
             args=['--output-json-path=/mock-checkout/output.json',
                   '--test-results-server=some.host', '--description', 'some description'])
         self._test_run_with_json_output(runner, port.host.filesystem, upload_succeeds=True)
         self.assertEqual(self._load_output_json(runner), [{
             "buildTime": "2013-02-08T15:19:37.460000", "description": "some description",
             "tests": self._event_target_wrapper_and_inspector_results,
             "revisions": {"chromium": {"timestamp": "2013-02-01 08:48:05 +0000", "revision": "5678"}}}])
 
-    def create_runner_and_setup_results_template(self, args=[]):
+    def create_runner_and_setup_results_template(self, args=None):
+        args = args or []
         runner, port = self.create_runner(args)
         filesystem = port.host.filesystem
         filesystem.write_text_file(
             runner._base_path + '/resources/results-template.html',  # pylint: disable=protected-access
             ('BEGIN<script src="%AbsolutePathToWebKitTrunk%/some.js"></script>'
              '<script src="%AbsolutePathToWebKitTrunk%/other.js"></script><script>%PeformanceTestsResultsJSON%</script>END'))
         filesystem.write_text_file(runner._base_path + '/Dromaeo/resources/dromaeo/web/lib/jquery-1.6.4.js', 'jquery content')
         return runner, port
 
     def test_run_respects_no_results(self):
@@ skipping 217 matching lines @@
         self._test_run_with_json_output(runner, port.host.filesystem, compare_logs=False)
         generated_json = json.loads(port.host.filesystem.files['/mock-checkout/output.json'])
         self.assertTrue(isinstance(generated_json, list))
         self.assertEqual(len(generated_json), 1)
 
         output = generated_json[0]['tests']['Bindings']['tests']['event-target-wrapper']['metrics']['Time']['current']
         self.assertEqual(len(output), 3)
         expectedMetrics = EventTargetWrapperTestData.results['metrics']['Time']['current'][0]
         for metrics in output:
             self.assertEqual(metrics, expectedMetrics)