Fix a typo for "--dry-run" in the usage message.

fetch.py

 #!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 """
 Tool to perform checkouts in one easy command line!
 
 Usage:
   fetch <recipe> [--property=value [--property2=value2 ...]]
@@ skipping 185 matching lines @@
 """
 usage: %s [options] <recipe> [--property=value [--property2=value2 ...]]
 
 This script can be used to download the Chromium sources. See
 http://www.chromium.org/developers/how-tos/get-the-code
 for full usage instructions.
 
 Valid options:
    -h, --help, help   Print this message.
    --nohooks          Don't run hooks after checkout.
-   -n, --dryrun       Don't run commands, only print them.
+   -n, --dry-run      Don't run commands, only print them.

[Dirk Pranke, 2014/02/11 17:19:33]

You're correctly identifying the bug: the usage doesn't match the actual flag
name.

However, the actual flag name is inconsistent w/ the field name in the options
object; python convention maps an option name with a dash in it to an underscore
(so it should be options.dry_run, not options.dryrun).

We should also the code to be options.dry_run. That may be more than you wanted
to bite off in this simple little fix; if so let me know, as this otherwise lgtm
and I can fix the field name in a follow-up patch.

[wtc, 2014/02/11 19:15:13]

I'll be happy to make this change. But the CL is on my home computer, so I won't
be able to upload a new patch set until tomorrow morning.

 """ % os.path.basename(sys.argv[0]))
   sys.exit(bool(msg))
 
 
 def handle_args(argv):
   """Gets the recipe name from the command line arguments."""
   if len(argv) <= 1:
     usage('Must specify a recipe.')
   if argv[1] in ('-h', '--help', 'help'):
     usage()
@@ skipping 73 matching lines @@
 
 
 def main():
   options, recipe, props = handle_args(sys.argv)
   spec, root = run_recipe_fetch(recipe, props)
   return run(options, spec, root)
 
 
 if __name__ == '__main__':
   sys.exit(main())