Add Element securitypolicyviolation_event (#12333)
Add Element securitypolicyviolation_event (#12333)

* Add Element securitypolicyviolation_event

* Add spec url for the securitypolicyviolation
chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data