Chrome Version: 61.0.3163.120
OS: Win7, ChromeOS

The list of languages that can be set as Chrome UI language includes 14 languages that cannot be selected by the user. Hence it is not possible through normal user interactions to set them as UI languages.

A user can only add languages via Settings, by clicking on the "Add languages" link.

We should consider making some of these languages available in order to benefit the user.

This is the list:

ar-LB
ar-DZ
ar-EH
ar-TN
ar-LY
ar-SO
ar-MR
ar-SA
ar-MA
en-150
en-HK
en-SG
ro-MD
sr-Latn