Note that the Storage Access API will surface a browser permission prompt to users. To provide an optimal user experience, we will only prompt the user if the site calling requestStorageAccess() has interacted with the embedded page and has previously visited the third-party site in a top-level context. A successful grant will allow cross-site cookie access for that site for 30 days. Potential use cases are authenticated cross-site embeds such as social network commenting widgets, payment providers, subscribed video services.