The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/dd72f0753a12a621374d78ed911949aed70ec7e3

commit dd72f0753a12a621374d78ed911949aed70ec7e3
Author: Lutz Justen <ljusten@chromium.org>
Date: Wed Dec 19 05:33:26 2018

authpolicy: Set OS name and version during join

Sets the operating system name and version during domain join.
Note that the version in Active Directory will stay at the version at
domain join time, it won't be updated if the device is patched.

BUG= chromium:914302 
TEST=Tested on device/server

Change-Id: Id174f9d1c194ab18bdb86e83541b4e1aa40eb33a
Reviewed-on: https://chromium-review.googlesource.com/1373790
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Lutz Justen <ljusten@chromium.org>
Reviewed-by: Roman Sorokin <rsorokin@chromium.org>

[modify] https://crrev.com/dd72f0753a12a621374d78ed911949aed70ec7e3/authpolicy/samba_helper.cc
[modify] https://crrev.com/dd72f0753a12a621374d78ed911949aed70ec7e3/authpolicy/samba_helper.h
[modify] https://crrev.com/dd72f0753a12a621374d78ed911949aed70ec7e3/authpolicy/samba_interface.cc

To verify:
- Join a Chrome OS device to AD
- On AD server, open Users And Computers
- Search the machine name you added
- Right-click and select Properties
- Select Operating System tab

Name should say "Chrome OS".
Version should be something like 73.11342.0.1234.
Service pack should be None.