Minor refactoring: Move set-up of host and port into update_w3c_test_expectations.py.

third_party/WebKit/Tools/Scripts/webkitpy/w3c/update_w3c_test_expectations.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Functionality for adding TestExpectations lines and downloading baselines
 based on layout test failures in try jobs.
 
 This script is used as part of the w3c test auto-import process.
 """
 
 import logging
 
 from webkitpy.common.net import rietveld
 from webkitpy.common.net.buildbot import BuildBot
 from webkitpy.common.webkit_finder import WebKitFinder
 from webkitpy.w3c.test_parser import TestParser
 
 _log = logging.getLogger(__name__)
 
 
-def main(host, port):
+def main(host):
+    host.initialize_scm()
+    port = host.port_factory.get()
     expectations_file = port.path_to_generic_test_expectations_file()
     expectations_line_adder = W3CExpectationsLineAdder(host)
     issue_number = expectations_line_adder.get_issue_number()
     try_bots = expectations_line_adder.get_try_bots()
     try_jobs = rietveld.latest_try_jobs(issue_number, try_bots, host.web)
     test_expectations = {}
     if not try_jobs:
         print 'No Try Job information was collected.'
         return 1
 
@@ skipping 291 matching lines @@
                 for platform in tests_results[test_path].keys():
                     if tests_results[test_path][platform]['actual'] not in ['CRASH', 'TIMEOUT']:
                         del tests_results[test_path][platform]
                         tests_to_rebaseline.add(test_path)
         return list(tests_to_rebaseline), tests_results
 
     def is_js_test(self, webkit_finder, test_path):
         absolute_path = self._host.filesystem.join(webkit_finder.chromium_base(), test_path)
         test_parser = TestParser(absolute_path, self._host)
         return test_parser.is_jstest()