$ sudo apt-get update
$ sudo apt-get install linux-headers-chromebook 

linux-headers-chromebook is installed in your system.

Make ensure the linux-headers-chromebook package were installed using the commands given below,

$ sudo dpkg-query -l | grep linux-headers-chromebook *

You will get with linux-headers-chromebook package name, version, architecture and description in a table

linux-headers-chromebook package basic information: