Issues with ChromeOS jobs

Split off from #159 (closed).

Our ChromeOS jobs are timing out:

https://builds.tuxbuild.com/29HRFiMsh6ezP5P2mXcKevsbgRc/ https://builds.tuxbuild.com/29HRFi8ijM9RYjQLfSbveNV9WGS/ https://builds.tuxbuild.com/29HTkBedgPByR6XbaG5cq56vVxq/ https://builds.tuxbuild.com/29HTkDDBM8P5lWRtyzEvNnS1v5P/ https://builds.tuxbuild.com/29HYYX7sSLQABigjqUZdnjQLc9K/ https://builds.tuxbuild.com/29HYYZhL4Y9odMgSU7qFeTUi7mH/ https://builds.tuxbuild.com/29HZDZD3z4tW1MgqbWpOM7Rp6Yn/ https://builds.tuxbuild.com/29HZDfIwMaFNvd8qIi80wV73ccc/

@stylesen said this is due to the ChromeOS repo size. For now, we will disable our ChromeOS jobs:

https://github.com/ClangBuiltLinux/continuous-integration2/pull/366