Computer Configuration > Administrative Templates > Google Chrome
Both
HKLM\Software\Policies\Google\Chrome
https://github.com/w3c/ServiceWorker/issues/765 asks srcdoc iframe with the "allow-same-origin" sandbox attribute to be under ServiceWorker control. Setting the policy to Enabled or leaving it unset means Google Chrome makes srcdoc iframes with "allow-same-origin" sandbox attributes to be under ServiceWorker control. Setting the policy to Disabled leaves the srcdoc iframe not controlled by ServiceWorker. This policy is intended to be temporary and will be removed in 2026.