Remove ignored bot_update "force" parameter.

scripts/slave/recipe_modules/chromium_checkout/api.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.
 
 from recipe_engine import recipe_api
 
 
 class ChromiumCheckoutApi(recipe_api.RecipeApi):
   def __init__(self, *args, **kwargs):
     super(ChromiumCheckoutApi, self).__init__(*args, **kwargs)
@@ skipping 36 matching lines @@
         self.m.properties.get('patch_project'))
     if not cwd and self.working_dir:
       cwd = self.working_dir.join(patch_root)
     files = self.m.tryserver.get_files_affected_by_patch(patch_root, cwd=cwd)
     for i, path in enumerate(files):
       path = str(path)
       assert path.startswith(relative_to)
       files[i] = path[len(relative_to):]
     return files
 
-  def ensure_checkout(self, bot_config, root_solution_revision=None,
-                      force=False):
+  def ensure_checkout(self, bot_config, root_solution_revision=None):
     """Wrapper for bot_update.ensure_checkout with chromium-specific additions.
     """
     if self.m.platform.is_win:
       self.m.chromium.taskkill()
 
     kwargs = {}
     self._working_dir = self.get_checkout_dir(bot_config)
     if self._working_dir:
       kwargs['cwd'] = self._working_dir
 
     if self.m.platform.is_linux:
       kwargs['env'] = {'GCLIENT_KILL_GIT_FETCH_AFTER': '1200'}  # 20 minutes.
 
     # 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)
+        **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'])
 
     return update_step