Change ChromiumCommit.format_patch to use a filtered list of files

third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_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 unittest
 
 from webkitpy.common.host_mock import MockHost
 from webkitpy.common.system.executive_mock import MockExecutive2
 from webkitpy.w3c.chromium_commit import ChromiumCommit
 from webkitpy.w3c.test_exporter import TestExporter
 from webkitpy.w3c.wpt_github_mock import MockWPTGitHub
 
 
 def mock_command_exec(vals):
     def run_fn(args):
         sub_command = args[1]
         return vals.get(sub_command, '')
     return MockExecutive2(run_command_fn=run_fn)
 
 
-
 class TestExporterTest(unittest.TestCase):
 
     def setUp(self):
         self.host = MockHost()
         self.wpt_github = MockWPTGitHub(pull_requests=[])
 
     def test_stops_if_more_than_one_pr_is_in_flight(self):
         host = MockHost()
         wpt_github = MockWPTGitHub(pull_requests=[{'id': 1}, {'id': 2}])
 
@@ skipping 115 matching lines @@
         })
         wpt_github = MockWPTGitHub(pull_requests=[])
         test_exporter = TestExporter(self.host, wpt_github)
 
         commits = test_exporter.exportable_commits_since('beefcafe')
         self.assertEqual(len(commits), 0)
         self.assertEqual(self.host.executive.calls, [
             ['git', 'rev-parse', '--show-toplevel'],
             ['git', 'rev-list', 'beefcafe..HEAD', '--reverse', '--', 'badbeef8/third_party/WebKit/LayoutTests/imported/wpt/'],
             ['git', 'show', '--format=%B', '--no-patch', 'badbeef8']])