rebaseline.py: in option names, replace underscores with hyphens

tools/rebaseline.py

 #!/usr/bin/python
 
 '''
 Copyright 2012 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 '''
 
 '''
@@ skipping 241 matching lines @@
                                             outfilename=outfilename)
 
 # main...
 
 parser = argparse.ArgumentParser()
 parser.add_argument('--configs', metavar='CONFIG', nargs='+',
                     help='which configurations to rebaseline, e.g. ' +
                     '"--configs 565 8888"; if unspecified, run a default ' +
                     'set of configs. This should ONLY be specified if ' +
                     '--tests has also been specified.')
-parser.add_argument('--dry_run', action='store_true',
+parser.add_argument('--dry-run', action='store_true',
                     help='instead of actually downloading files or adding ' +
                     'files to checkout, display a list of operations that ' +
                     'we would normally perform')
-parser.add_argument('--json_base_url',
+parser.add_argument('--json-base-url',
                     help='base URL from which to read JSON_FILENAME ' +
                     'files; defaults to %(default)s',
                     default='http://skia-autogen.googlecode.com/svn/gm-actual')
-parser.add_argument('--json_filename',
+parser.add_argument('--json-filename',
                     help='filename (under JSON_BASE_URL) to read a summary ' +
                     'of results from; defaults to %(default)s',
                     default='actual-results.json')
 parser.add_argument('--subdirs', metavar='SUBDIR', nargs='+',
                     help='which platform subdirectories to rebaseline; ' +
                     'if unspecified, rebaseline all subdirs, same as ' +
                     '"--subdirs %s"' % ' '.join(sorted(SUBDIR_MAPPING.keys())))
 parser.add_argument('--tests', metavar='TEST', nargs='+',
                     help='which tests to rebaseline, e.g. ' +
                     '"--tests aaclip bigmatrix"; if unspecified, then all ' +
                     'failing tests (according to the actual-results.json ' +
                     'file) will be rebaselined.')
 args = parser.parse_args()
 rebaseliner = Rebaseliner(tests=args.tests, configs=args.configs,
                           subdirs=args.subdirs, dry_run=args.dry_run,
                           json_base_url=args.json_base_url,
                           json_filename=args.json_filename)
 rebaseliner.RebaselineAll()