Add --gerrit_no_reset for who need to use FETCH_HEAD revision.

recipe_modules/bot_update/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.
 
 
 """Recipe module to ensure a checkout is consistant on a bot."""
 
 from recipe_engine import recipe_api
 
 
@@ skipping 42 matching lines @@
   def last_returned_properties(self):
       return self._last_returned_properties
 
   def ensure_checkout(self, gclient_config=None, suffix=None,
                       patch=True, update_presentation=True,
                       force=False, patch_root=None, no_shallow=False,
                       with_branch_heads=False, refs=None,
                       patch_project_roots=None, patch_oauth2=False,
                       output_manifest=True, clobber=False,
                       root_solution_revision=None, rietveld=None, issue=None,
-                      patchset=None, **kwargs):
+                      patchset=None, gerrit_no_reset=False, **kwargs):
     """
     Args:
       gclient_config: The gclient configuration to use when running bot_update.
         If omitted, the current gclient configuration is used.
       rietveld: The rietveld server to use. If omitted, will infer from
         the 'rietveld' property.
       issue: The rietveld issue number to use. If omitted, will infer from
         the 'issue' property.
       patchset: The rietveld issue patchset to use. If omitted, will infer from
         the 'patchset' property.
@@ skipping 119 matching lines @@
     if clobber:
       cmd.append('--clobber')
     if force:
       cmd.append('--force')
     if no_shallow:
       cmd.append('--no_shallow')
     if output_manifest:
       cmd.append('--output_manifest')
     if with_branch_heads or cfg.with_branch_heads:
       cmd.append('--with_branch_heads')
+    if gerrit_no_reset:
+      cmd.append('--gerrit_no_reset')
 
     # Inject Json output for testing.
     git_mode = self._mastername not in SVN_MASTERS
     first_sln = cfg.solutions[0].name
     step_test_data = lambda: self.test_api.output_json(
         master, builder, slave, root, first_sln, rev_map, git_mode, force,
         self._fail_patch,
         output_manifest=output_manifest, fixed_revisions=fixed_revisions)
 
     # Add suffixes to the step name, if specified.
@@ skipping 55 matching lines @@
 
       # bot_update actually just sets root to be the folder name of the
       # first solution.
       if step_result.json.output['did_run']:
         co_root = step_result.json.output['root']
         cwd = kwargs.get('cwd', self.m.path['slave_build'])
         if 'checkout' not in self.m.path:
           self.m.path['checkout'] = cwd.join(*co_root.split(self.m.path.sep))
 
     return step_result