Add option to disable upload

Change-Id: I5ecb33db771728b6a7c70e476f3e0b8d25e9872d
diff --git a/tools/git_sync_cl_chain.py b/tools/git_sync_cl_chain.py
index ca17e32..ef10a73 100755
--- a/tools/git_sync_cl_chain.py
+++ b/tools/git_sync_cl_chain.py
@@ -44,8 +44,10 @@
   result.add_option('--rebase',
                     help='To use `git pull --rebase` instead of `git pull`',
                     action='store_true')
+  result.add_option('--no_upload', '--no-upload',
+                    help='Disable uploading to Gerrit', action='store_true')
   (options, args) = result.parse_args(argv)
-  print(options)
+  options.upload = not options.no_upload
   assert options.message, 'A message for the patchset is required.'
   assert len(args) == 0
   return options
@@ -81,7 +83,8 @@
       print('Syncing ' + branch.name)
       utils.RunCmd(['git', 'checkout', branch.name], quiet=True)
       utils.RunCmd(['git', 'pull'] + rebase_args, quiet=True)
-      utils.RunCmd(['git', 'cl', 'upload', '-m', options.message], quiet=True)
+      if options.upload:
+        utils.RunCmd(['git', 'cl', 'upload', '-m', options.message], quiet=True)
 
     utils.RunCmd(['git', 'cl', 'issue'])