When uploading updates to baselines/expectations, pass patchset title with "-t".

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

 # Copyright 2014 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.
 
 """Fetches a copy of the latest state of a W3C test repository and commits.
 
 If this script is given the argument --auto-update, it will also:
  1. Upload a CL.
  2. Trigger try jobs and wait for them to complete.
  3. Make any changes that are required for new failing tests.
@@ skipping 411 matching lines @@
             message_lines.extend('  ' + d for d in directories)
         return '\n'.join(message_lines)
 
     def fetch_new_expectations_and_baselines(self):
         """Adds new expectations and downloads baselines based on try job results, then commits and uploads the change."""
         _log.info('Adding test expectations lines to LayoutTests/TestExpectations.')
         expectation_updater = WPTExpectationsUpdater(self.host)
         expectation_updater.run(args=[])
         message = 'Update test expectations and baselines.'
         self.check_run(['git', 'commit', '-a', '-m', message])
-        self.git_cl.run(['upload', '-m', message, '--gerrit'])
+        self.git_cl.run(['upload', '-t', message, '--gerrit'])

[tandrii(chromium), 2017/03/02 14:49:28]

this will work for re-upload, but for initial upload. For now, you'd need to do
smth like:
 if git_cl.run('issue'):
   git_cl.run(['upload', '-t', message, '--gerrit'])
 else:
   git_cl.run(['upload', '-m', message, '--gerrit'])

 
     def update_all_test_expectations_files(self, deleted_tests, renamed_tests):
         """Updates all test expectations files for tests that have been deleted or renamed."""
         port = self.host.port_factory.get()
         for path, file_contents in port.all_expectations_dict().iteritems():
             parser = TestExpectationParser(port, all_tests=None, is_lint_mode=False)
             expectation_lines = parser.parse(path, file_contents)
             self._update_single_test_expectations_file(path, expectation_lines, deleted_tests, renamed_tests)
 
     def _update_single_test_expectations_file(self, path, expectation_lines, deleted_tests, renamed_tests):
@@ skipping 31 matching lines @@
         """Returns a dict mapping source to dest name for layout tests that have been renamed."""
         out = self.check_run(['git', 'diff', 'origin/master', '-M100%', '--diff-filter=R', '--name-status'])
         renamed_tests = {}
         for line in out.splitlines():
             _, source_path, dest_path = line.split()
             source_test = self.finder.layout_test_name(source_path)
             dest_test = self.finder.layout_test_name(dest_path)
             if source_test and dest_test:
                 renamed_tests[source_test] = dest_test
         return renamed_tests