Seems that there's a dev image out there that rotates the screen 90 at boot

https://feedback.corp.google.com/product/208/neutron?lView=rd&lReport=60874540983

https://www.reddit.com/r/chromeos/comments/6bskuv/chromebook_plus_dev_update_60031000_with_android/

Key	Value
CHROME VERSION	
60.0.3100.0 dev
CHROMEOS_AUSERVER	
<URL: 1>
CHROMEOS_RELEASE_BOARD	
caroline-signed-mpkeys
CHROMEOS_RELEASE_DESCRIPTION	
9554.2.0 (Official Build) dev-channel caroline
CHROMEOS_RELEASE_TRACK	
dev-channel
CHROMEOS_RELEASE_VERSION	
9554.2.0