Make rebase and sync the default for Gerrit updates

recipe_modules/bot_update/resources/bot_update.py

 #!/usr/bin/env python
 # 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.
 
 # TODO(hinoka): Use logging.
 
 import cStringIO
 import codecs
 import collections
@@ skipping 1396 matching lines @@
   parse.add_option('--patch_url', help='Optional URL to SVN patch.')
   parse.add_option('--root', dest='patch_root',
                    help='DEPRECATED: Use --patch_root.')
   parse.add_option('--patch_root', help='Directory to patch on top of.')
   parse.add_option('--rietveld_server',
                    default='codereview.chromium.org',
                    help='Rietveld server.')
   parse.add_option('--gerrit_repo',
                    help='Gerrit repository to pull the ref from.')
   parse.add_option('--gerrit_ref', help='Gerrit ref to apply.')
-  parse.add_option('--gerrit_rebase_patch_ref', action='store_true',
-                   help='Rebase Gerrit patch ref after of checking it out.')
+  parse.add_option('--gerrit_no_rebase_patch_ref', action='store_true',
+                   help='Bypass rebase of Gerrit patch ref after checkout.')
   parse.add_option('--gerrit_no_reset', action='store_true',
                    help='Bypass calling reset after applying a gerrit ref.')
   parse.add_option('--specs', help='Gcilent spec.')
   parse.add_option('--master',
                    help='Master name. If specified and it is not in '
                         'bot_update\'s whitelist, bot_update will be noop.')
   parse.add_option('-f', '--force', action='store_true',
                    help='Bypass check to see if we want to be run. '
                         'Should ONLY be used locally or by smart recipes.')
   parse.add_option('--revision_mapping',
@@ skipping 141 matching lines @@
           target_os_only=specs.get('target_os_only', False),
 
           # Then, pass in information about how to patch.
           patch_root=options.patch_root,
           issue=options.issue,
           patchset=options.patchset,
           patch_url=options.patch_url,
           rietveld_server=options.rietveld_server,
           gerrit_repo=options.gerrit_repo,
           gerrit_ref=options.gerrit_ref,
-          gerrit_rebase_patch_ref=options.gerrit_rebase_patch_ref,
+          gerrit_rebase_patch_ref=not options.gerrit_no_rebase_patch_ref,
           revision_mapping=options.revision_mapping,
           apply_issue_email_file=options.apply_issue_email_file,
           apply_issue_key_file=options.apply_issue_key_file,
 
           # For official builders.
           buildspec=buildspec,
           gyp_env=options.gyp_env,
           runhooks=not options.no_runhooks,
 
           # Finally, extra configurations such as shallowness of the clone.
@@ skipping 144 matching lines @@
   except Exception:
     # Unexpected failure.
     emit_flag(options.flag_file)
     raise
   else:
     emit_flag(options.flag_file)
 
 
 if __name__ == '__main__':
   sys.exit(main())