blink_downstream: prepare for remote_run conversion

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 112 matching lines @@
       # (3) 'HEAD' for forced builds with unspecified 'revision'.
       # TODO(machenbach): Use parent_got_cr_revision on testers with component
       # builds to match also the chromium revision from the builder.
       component_rev = self.m.properties.get('revision') or 'HEAD'
       if bot_type == 'tester':
         component_rev = self.m.properties.get(
             'parent_got_revision', component_rev)
       dep = bot_config.get('set_component_rev')
       self.m.gclient.c.revisions[dep['name']] = dep['rev_str'] % component_rev
 
+  def get_checkout_dir(self, bot_config):
+    try:
+      builder_cache = self.m.path['builder_cache']
+    except KeyError:  # no-op if builder cache is not set up.
+      return None
+    else:
+      sanitized_buildername = ''.join(
+          c if c.isalnum() else '_' for c in self.m.properties['buildername'])
+      checkout_dir = builder_cache.join(
+          bot_config.get('checkout_dir', sanitized_buildername))
+      self.m.shutil.makedirs('checkout path', checkout_dir)
+      return checkout_dir
+
   def ensure_checkout(self, bot_config, root_solution_revision=None,
                       force=False):
     if self.m.platform.is_win:
       self.m.chromium.taskkill()
 
     kwargs = {}
-    try:
-      builder_cache = self.m.path['builder_cache']
-    except KeyError:  # no-op if builder cache is not set up.
-      pass
-    else:
-      sanitized_buildername = ''.join(
-          c if c.isalnum() else '_' for c in self.m.properties['buildername'])
-      checkout_path = builder_cache.join(
-          bot_config.get('checkout_dir', sanitized_buildername))
-      self.m.shutil.makedirs('checkout path', checkout_path)
-      kwargs['cwd'] = checkout_path
-      self._working_dir = checkout_path
+    self._working_dir = self.get_checkout_dir(bot_config)
+    if self._working_dir:
+      kwargs['cwd'] = self._working_dir
 
     # Bot Update re-uses the gclient configs.
     update_step = self.m.bot_update.ensure_checkout(
         patch_root=bot_config.get('patch_root'),
         root_solution_revision=root_solution_revision,
         clobber=bot_config.get('clobber', False),
         force=force, **kwargs)
     assert update_step.json.output['did_run']
     # HACK(dnj): Remove after 'crbug.com/398105' has landed
     self.m.chromium.set_build_properties(update_step.json.output['properties'])
@@ skipping 647 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()