cros_sysroot_utils: Remove --chrome-only.

Remove the --chrome-only argument only used by setup-board if
--chrome-binhost-only is set.

BUG=chromium:873260
TEST=run_tests
CQ-DEPEND=CL:1227572

Change-Id: Ibedf8ce0bea2c2b4e64bfcf188481f6c6d393fef
Reviewed-on: https://chromium-review.googlesource.com/1226181
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_sysroot_utils.py b/scripts/cros_sysroot_utils.py
index 77f01b8..60b8171 100644
--- a/scripts/cros_sysroot_utils.py
+++ b/scripts/cros_sysroot_utils.py
@@ -55,8 +55,6 @@
                        help='File to write the configuration into. If not '
                        'specified, the configuration will be printed to '
                        'stdout.')
-  binhost.add_argument('--chrome-only', dest='chrome_only', action='store_true',
-                       help='Generate only the chrome binhost.')
   binhost.add_argument('--local-only', dest='local_only', action='store_true',
                        help='Use compatible local boards only.')
   binhost.set_defaults(command='generate-binhosts')
@@ -89,5 +87,4 @@
   elif opts.command == 'generate-make-conf':
     output.write('\n' + sysroot.GenerateMakeConf(opts.accepted_licenses))
   elif opts.command == 'generate-binhosts':
-    output.write('\n' + sysroot.GenerateBinhostConf(opts.chrome_only,
-                                                    opts.local_only))
+    output.write('\n' + sysroot.GenerateBinhostConf(opts.local_only))