Don't access Port._filesystem directly (use Port.host.filesystem instead).

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.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.
 
 import json
 import optparse
 
 from webkitpy.common.net.buildbot import Build
 from webkitpy.common.net.rietveld import Rietveld
 from webkitpy.common.net.web_mock import MockWeb
@@ skipping 48 matching lines @@
 
         # Write to the mock filesystem so that these tests are considered to exist.
         port = self.mac_port
         tests = [
             'fast/dom/prototype-taco.html',
             'fast/dom/prototype-inheritance.html',
             'svg/dynamic-updates/SVGFEDropShadowElement-dom-stdDeviation-attr.html',
         ]
         for test in tests:
             # pylint: disable=protected-access
-            self._write(port._filesystem.join(port.layout_tests_dir(), test), 'contents')
+            self._write(port.host.filesystem.join(port.layout_tests_dir(), test), 'contents')
 
     def tearDown(self):
         BaseTestCase.tearDown(self)
         LoggingTestCase.tearDown(self)
 
     @staticmethod
     def command_options(**kwargs):
         options = {
             'only_changed_tests': False,
             'dry_run': False,
@@ skipping 78 matching lines @@
         self.assertEqual(self.tool.executive.calls[0], ['git', 'cl', 'try', '-b', 'MOCK Try Linux'])
 
     def test_rebaseline_calls(self):
         """Tests the list of commands that are invoked when rebaseline is called."""
         # First write test contents to the mock filesystem so that
         # fast/dom/prototype-taco.html is considered a real test to rebaseline.
         # TODO(qyearsley): Change this to avoid accessing protected methods.
         # pylint: disable=protected-access
         port = self.tool.port_factory.get('test-win-win7')
         self._write(
-            port._filesystem.join(port.layout_tests_dir(), 'fast/dom/prototype-taco.html'),
+            port.host.filesystem.join(port.layout_tests_dir(), 'fast/dom/prototype-taco.html'),
             'test contents')
 
         self.command._rebaseline(
             self.command_options(issue=11112222),
             {"fast/dom/prototype-taco.html": {Build("MOCK Try Win", 5000): ["txt", "png"]}})
 
         self.assertEqual(
             self.tool.executive.calls,
             [
                 [['python', 'echo', 'copy-existing-baselines-internal', '--suffixes', 'txt',
                   '--builder', 'MOCK Try Win', '--test', 'fast/dom/prototype-taco.html', '--build-number', '5000']],
                 [['python', 'echo', 'rebaseline-test-internal', '--suffixes', 'txt',
                   '--builder', 'MOCK Try Win', '--test', 'fast/dom/prototype-taco.html', '--build-number', '5000']],
                 [['python', 'echo', 'optimize-baselines', '--no-modify-scm', '--suffixes', 'txt', 'fast/dom/prototype-taco.html']]
             ])