We I try to use thinlto on Chrome for ChromeOS, I got.
Do we need to set is_chromeos=true in the ebuild file?

chromeos-chrome-61.0.3142.0_rc-r1: ERROR at //build/config/compiler/BUILD.gn:484:5: Assertion failed.
chromeos-chrome-61.0.3142.0_rc-r1:     assert(use_lld || is_chromeos, "gold plugin only supported with ChromeOS")
chromeos-chrome-61.0.3142.0_rc-r1:     ^-----
chromeos-chrome-61.0.3142.0_rc-r1: gold plugin only supported with ChromeOS
chromeos-chrome-61.0.3142.0_rc-r1: See //build/config/BUILDCONFIG.gn:510:3: which caused the file to be included.
chromeos-chrome-61.0.3142.0_rc-r1:   "//build/config/compiler:afdo",