chromium_tests: use correct cwd for deapplying patch

scripts/slave/recipe_modules/chromium_tests/api.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.
 
 import contextlib
 import copy
 import itertools
 import json
 
 from recipe_engine.types import freeze
@@ skipping 626 matching lines @@
     # We only override first solution here to make sure that we correctly revert
     # changes to DEPS file, which is particularly important for auto-rolls. It
     # is also imporant that we do not assume that corresponding revision is
     # stored in the 'got_revision' as some gclient configs change the default
     # mapping for their own purposes.
     first_solution_name = self.m.gclient.c.solutions[0].name
     rev_property = self.m.gclient.c.got_revision_mapping[first_solution_name]
     self.m.gclient.c.revisions[first_solution_name] = str(
         bot_update_json['properties'][rev_property])
     self._resolve_fixed_revisions(bot_update_json)
+
+    kwargs = {}
+    if self._working_dir:
+      kwargs['cwd'] = self._working_dir
+
     self.m.bot_update.ensure_checkout(
-        force=True, patch=False, update_presentation=False)
+        force=True, patch=False, update_presentation=False, **kwargs)
     self.m.chromium.runhooks(name='runhooks (without patch)')
 
   def run_tests_on_tryserver(self, bot_config, api, tests, bot_update_step,
                              affected_files, mb_mastername=None,
                              mb_buildername=None):
     def deapply_patch_fn(failing_tests):
       self.deapply_patch(bot_update_step)
       compile_targets = list(itertools.chain(
           *[t.compile_targets(api) for t in failing_tests]))
       if compile_targets:
@@ skipping 153 matching lines @@
 
     if not tests:
       return
 
     api.chromium_swarming.configure_swarming(
         'chromium', precommit=False, mastername=mastername)
     test_runner = api.chromium_tests.create_test_runner(
         api, tests, serialize_tests=bot_config.get('serialize_tests'))
     with api.chromium_tests.wrap_chromium_tests(bot_config, tests):
       test_runner()