Added hyphen-only options

Some options have words separated by underscores. Added options with
same name and underscores replaced by hyphens.

BUG=400953

Review URL: https://codereview.chromium.org/436963005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@288366 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/git_cache.py b/git_cache.py
index 1fa7e45..7ebe580 100755
--- a/git_cache.py
+++ b/git_cache.py
@@ -522,7 +522,7 @@
 
   # First, we need to ensure the cache is populated.
   populate_args = args[:]
-  populate_args.append('--no_bootstrap')
+  populate_args.append('--no-bootstrap')
   CMDpopulate(parser, populate_args)
 
   # Get the repo directory.
@@ -542,9 +542,11 @@
                     help='Only cache 10000 commits of history')
   parser.add_option('--ref', action='append',
                     help='Specify additional refs to be fetched')
-  parser.add_option('--no_bootstrap', action='store_true',
+  parser.add_option('--no_bootstrap', '--no-bootstrap',
+                    action='store_true',
                     help='Don\'t bootstrap from Google Storage')
-  parser.add_option('--ignore_locks', action='store_true',
+  parser.add_option('--ignore_locks', '--ignore-locks',
+                    action='store_true',
                     help='Don\'t try to lock repository')
 
   options, args = parser.parse_args(args)