The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/cf8d610f4f6b44a060268d801b8015708f75d620

commit cf8d610f4f6b44a060268d801b8015708f75d620
Author: Roman Sorokin <rsorokin@chromium.org>
Date: Tue Jan 23 09:48:44 2018

authpolicy: Add --kerberos param for net command

Switched executable params to long versions.

BUG= chromium:801200 
TEST=cros_run_unit_tests --board=amd64-generic --packages authpolicy

Change-Id: I9845ae7b54d2c1412388077f7d3c1f0e0e8f34b4
Reviewed-on: https://chromium-review.googlesource.com/860065
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Roman Sorokin <rsorokin@chromium.org>
Reviewed-by: Lutz Justen <ljusten@chromium.org>

[modify] https://crrev.com/cf8d610f4f6b44a060268d801b8015708f75d620/authpolicy/samba_helper.cc
[modify] https://crrev.com/cf8d610f4f6b44a060268d801b8015708f75d620/authpolicy/samba_helper.h
[modify] https://crrev.com/cf8d610f4f6b44a060268d801b8015708f75d620/authpolicy/samba_interface.cc
[modify] https://crrev.com/cf8d610f4f6b44a060268d801b8015708f75d620/authpolicy/stub_smbclient_main.cc
[modify] https://crrev.com/cf8d610f4f6b44a060268d801b8015708f75d620/authpolicy/stub_net_main.cc

Verified fixed. No kerberos auth while domain join:

localhost / # cat /var/log/authpolicy.1.log 
2018-04-10T14:16:46.060955-07:00 INFO authpolicyd[2950]: libminijail[2]: mount / -> / type ''
2018-04-10T14:16:46.060974-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /dev -> /dev type ''
2018-04-10T14:16:46.061002-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /sys -> /sys type ''
2018-04-10T14:16:46.061010-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /run -> /run type ''
2018-04-10T14:16:46.061019-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /var -> /var type ''
2018-04-10T14:16:46.061027-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /run/authpolicyd -> /run/authpolicyd type ''
2018-04-10T14:16:46.061036-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /var/lib/authpolicyd -> /var/lib/authpolicyd type ''
2018-04-10T14:16:46.061045-07:00 INFO authpolicyd[2950]: libminijail[2]: mount /var/lib/metrics -> /var/lib/metrics type ''
2018-04-10T14:16:46.068168-07:00 INFO authpolicyd[2950]: No install attributes found. Cleaning state.
2018-04-10T14:16:46.068428-07:00 INFO authpolicyd[2950]: authpolicyd starting
2018-04-10T14:17:15.301982-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'JoinADDomain' request#033[0m
2018-04-10T14:17:36.382162-07:00 INFO authpolicyd[2950]: Wrote machine password file '/var/lib/authpolicyd/machine_pass'
2018-04-10T14:17:36.382418-07:00 INFO authpolicyd[2950]: Wrote configuration file '/var/lib/authpolicyd/config.dat'
2018-04-10T14:17:36.382481-07:00 INFO authpolicyd[2950]: JoinADDomain succeeded
2018-04-10T14:17:36.385608-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'RefreshDevicePolicy' request#033[0m
2018-04-10T14:17:42.565214-07:00 INFO authpolicyd[2950]: Getting device GPO list for device account
2018-04-10T14:17:54.029599-07:00 INFO authpolicyd[2950]: Device policy fetch and parsing succeeded
2018-04-10T14:17:54.029670-07:00 INFO authpolicyd[2950]: Device is not locked yet. Caching device policy.
2018-04-10T14:17:58.866786-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'RefreshDevicePolicy' request#033[0m
2018-04-10T14:17:58.866810-07:00 INFO authpolicyd[2950]: Using cached policy
2018-04-10T14:17:58.878796-07:00 INFO authpolicyd[2950]: All 1 calls to StoreUnsignedPolicyEx succeeded.
2018-04-10T14:18:02.417709-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'RefreshDevicePolicy' request#033[0m
2018-04-10T14:18:07.958885-07:00 INFO authpolicyd[2950]: Getting device GPO list for device account
2018-04-10T14:18:17.975050-07:00 INFO authpolicyd[2950]: Device policy fetch and parsing succeeded
2018-04-10T14:18:17.992653-07:00 INFO authpolicyd[2950]: All 1 calls to StoreUnsignedPolicyEx succeeded.
localhost / # 

Kerberos auth while user login:

localhost / # cat /var/log/authpolicy.log 
2018-04-10T14:19:27.549987-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'AuthenticateUser' request#033[0m
2018-04-10T14:19:33.668812-07:00 INFO authpolicyd[2950]: Firing signal UserKerberosFilesChanged
2018-04-10T14:19:40.037316-07:00 INFO authpolicyd[2950]: TGT RENEWAL - Scheduling renewal in 7h 59m 54s (valid for 9h 59m 53s, renewable for 167h 59m 52s)
2018-04-10T14:19:40.037407-07:00 INFO authpolicyd[2950]: AuthenticateUser succeeded
2018-04-10T14:19:41.545321-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'GetUserStatus' request#033[0m
2018-04-10T14:19:50.745776-07:00 INFO authpolicyd[2950]: GetUserStatus succeeded
2018-04-10T14:19:50.746153-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'GetUserKerberosFiles' request#033[0m
2018-04-10T14:19:50.746311-07:00 INFO authpolicyd[2950]: GetUserKerberosFiles succeeded
2018-04-10T14:19:50.746739-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'RefreshUserPolicy' request#033[0m
2018-04-10T14:19:55.969642-07:00 INFO authpolicyd[2950]: Getting user GPO list for user account
2018-04-10T14:20:04.274335-07:00 INFO authpolicyd[2950]: User policy fetch and parsing succeeded
2018-04-10T14:20:04.279232-07:00 INFO authpolicyd[2950]: All 1 calls to StoreUnsignedPolicyEx succeeded.
2018-04-10T14:26:20.538363-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'AuthenticateUser' request#033[0m
2018-04-10T14:26:28.419853-07:00 INFO authpolicyd[2950]: TGT RENEWAL - Scheduling renewal in 7h 59m 59s (valid for 9h 59m 59s, renewable for 167h 59m 59s)
2018-04-10T14:26:28.419925-07:00 INFO authpolicyd[2950]: Firing signal UserKerberosFilesChanged
2018-04-10T14:26:39.419525-07:00 INFO authpolicyd[2950]: AuthenticateUser succeeded
2018-04-10T14:26:39.420266-07:00 INFO authpolicyd[2950]: #033[41;1;97mReceived 'GetUserKerberosFiles' request#033[0m
2018-04-10T14:26:39.420685-07:00 INFO authpolicyd[2950]: GetUserKerberosFiles succeeded
localhost / # 

Chrome OS: 10452.52.0
Chrome: 66.0.3359.94
Device: Santa