Remove ChromeOS specific files from libweave repo

Change-Id: Id7dae764d21d52afc1d9a46292f0cad82d21903c
Reviewed-on: https://weave-review.googlesource.com/1330
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
(cherry picked from commit 35fb87b830270adaf3b24b18cb43db8debb62bd8)
Reviewed-on: https://weave-review.googlesource.com/1345
Reviewed-by: Vitaly Buka <vitalybuka@google.com>