sync_chrome: drop --ignore_locks option

This has been removed from gclient, so passing it down isn't useful.
Remove it from our side too.

BUG=chromium:1049610
TEST=`emerge-$BOARD chrome-icu` still works

Cq-Depend: chromium:2314956
Change-Id: Ie079b2520b1537438a08191284e4fa4c2b1e13f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2314679
Reviewed-by: George Engelbrecht <engeg@google.com>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/sync_chrome.py b/scripts/sync_chrome.py
index aa50f67..edecb82 100644
--- a/scripts/sync_chrome.py
+++ b/scripts/sync_chrome.py
@@ -42,8 +42,6 @@
                       dest='use_cache', action='store_false')
   parser.add_argument('--git_cache_dir', type='path',
                       help='Define explicit git cache.')
-  parser.add_argument('--ignore_locks', help='Ignore git cache locks.',
-                      action='store_true', default=False)
   parser.add_argument('chrome_root', help='Directory to sync chrome in')
 
   return parser
@@ -55,8 +53,7 @@
                           options.internal, options.version,
                           options.gclient_template, options.use_cache,
                           git_cache_dir=options.git_cache_dir)
-  gclient.Sync(gclient_path, options.chrome_root, reset=options.reset,
-               ignore_locks=options.ignore_locks)
+  gclient.Sync(gclient_path, options.chrome_root, reset=options.reset)
 
 
 def main(argv):