chromium/components/policy/resources/templates/policy_definitions/Startup/policy_atomic_groups.yaml

Homepage:
  caption: Homepage
  policies:
  - HomepageLocation
  - HomepageIsNewTabPage
  - NewTabPageLocation
  - ShowHomeButton
RestoreOnStartup:
  caption: Action on startup
  owners:
  - file://components/policy/OWNERS
  - [email protected]
  policies:
  - RestoreOnStartup
  - RestoreOnStartupURLs