I found this tab for you which indicates that Robin does play it in drop-D tuning. I dont know if this tab is flawless but it seems good:
Chinese Democracy Tab by Guns N Roses,
www.Ultimate-Guitar.ComChinese Democracy by Guns N' Roses
main riff:
e--------------------------------------------------------------------
B--------------------------------------------------------------------
G--------------------------------------------------------------------
D--2-2---2-5-5-5-7-7-7-7-7-8-7----2-2---2-5-5-5-7-7-7-7-7-8----------
A--2-2---2-5-5-5-7-7-7-7-7-8-7----2-2---2-5-5-5-7-7-7-7-7-8----------
E--0-0---0-3-3-3-5-5-5-5-5-6-5----0-0---0-3-3-3-5-5-5-5-5-6----------
verse:
(bass)
G---------------------------------------------------------------------
D---------------------------------------------------------------------
A---------------------------------------------------------------------
E--0-0---0-3-3-3-5-5-5-5-5-6-5-----0-0---0-3-3-3-3-5-5-5-5-5-6--------
Chorus:
e---------------------------------------------------------
B---------------------------------------------------------
G---------------------------------------------------------
D--------9-99---11/7--------------------------------------
A--7-77--7-77---9-/5--------------------------------------
E--5-55---------------------------------------------------
more then we got, to rule the nation...
e------------------------------------------
B------------------------------------------
G------------------------------------------
D------------------------------------------
A---7--7--7-7-7-7---5-5-5--3---------------
E---5--5--5-5-5-5---3-3-3--1---------------
what I got is precious time...
and there you have it, durring the solo just play the verse bit, and on the outro
play the chorus riff. I think robin plays in in drop-D tuning though, so instead
of
a: ---- ... play a: ----... and such.
---- ----
---- ----
--2- --2-
--2- --2-