Add libchrome-host build target

Remote base/sys_info_chromeos.cc from the set of files we build for
both target and host libraries.  It's not obvious why we need this
file on Android, and we can't use it on host.

Bug: 22608897
Change-Id: Idcf8f4fd4bd46df6d99841c54e1bb59a734a0453
2 files changed