Update chrome://extensions for supervised users
This includes:
- new types of controlled-setting-indicator for children/supervised users
- corresponding new "controlled-by" strings
- passing the strings through the developerPrivate API, and removing the now-unnecessary installedByCustodian field
BUG=
397951
Committed:
https://crrev.com/5c654f86279e4abef018d89c8d94611fe8edacc0
Cr-Commit-Position: refs/heads/master@{#330928}