Add --upstream option to gclient to scrape git checkouts back to upstream state.

gclient.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Meta checkout manager supporting both Subversion and GIT.
 
 Files
   .gclient      : Current client configuration, written by 'config' command.
                   Format is a Python script defining 'solutions', a list whose
@@ skipping 1523 matching lines @@
   parser.add_option('-M', '--merge', action='store_true',
                     help='merge upstream changes instead of trying to '
                          'fast-forward or rebase')
   parser.add_option('--deps', dest='deps_os', metavar='OS_LIST',
                     help='override deps for the specified (comma-separated) '
                          'platform(s); \'all\' will process all deps_os '
                          'references')
   parser.add_option('-m', '--manually_grab_svn_rev', action='store_true',
                     help='Skip svn up whenever possible by requesting '
                          'actual HEAD revision from the repository')
+  parser.add_option('--upstream', action='store_true',
+                    help='Make repo state match upstream branch.')
   (options, args) = parser.parse_args(args)
   client = GClient.LoadCurrentConfig(options)
 
   if not client:
     raise gclient_utils.Error('client not configured; see \'gclient config\'')
 
   if options.revisions and options.head:
     # TODO(maruel): Make it a parser.error if it doesn't break any builder.
     print('Warning: you cannot use both --head and --revision')
 
@@ skipping 29 matching lines @@
   """Revert all modifications in every dependencies.
 
   That's the nuclear option to get back to a 'clean' state. It removes anything
   that shows up in svn status."""
   parser.add_option('--deps', dest='deps_os', metavar='OS_LIST',
                     help='override deps for the specified (comma-separated) '
                          'platform(s); \'all\' will process all deps_os '
                          'references')
   parser.add_option('-n', '--nohooks', action='store_true',
                     help='don\'t run hooks after the revert is complete')
+  parser.add_option('--upstream', action='store_true',
+                    help='Make repo state match upstream branch.')
   (options, args) = parser.parse_args(args)
   # --force is implied.
   options.force = True
   options.reset = False
   options.delete_unversioned_trees = False
   client = GClient.LoadCurrentConfig(options)
   if not client:
     raise gclient_utils.Error('client not configured; see \'gclient config\'')
   return client.RunOnDeps('revert', args)
 
@@ skipping 200 matching lines @@
   except (gclient_utils.Error, subprocess2.CalledProcessError), e:
     print >> sys.stderr, 'Error: %s' % str(e)
     return 1
 
 
 if '__main__' == __name__:
   fix_encoding.fix_encoding()
   sys.exit(Main(sys.argv[1:]))
 
 # vim: ts=2:sw=2:tw=80:et: