Privacy Sandbox and the deprecation of third-party cookies is right around the corner. Let's make sure the Playground <iframe> keeps working as these changes are rolled out.

Related:

• Setting "Block third-party cookies" breaks the embedded Playground (Chrome, Safari, Brave) #87
• Embed support with third-party cookies disabled #577
• "Block third party cookies" vs Privacy Sandbox

Noteworthy:

• The disable third-party cookies option in Chrome is not a good reflection of how Chrome is going to when when the third-party cookies deprecation becomes the default. Some things are still in flux.
• Storage Partitioning for service workers. My understanding is that Partitioned Service Workers should just work without any changes in Playground
• Origin trials make it possible to enable some of these experimental new features on specific sites, like playground.wordpress.net. I wanted to sign up for the storage, but they aren’t active trials at the moment unfortunately.
• Chromestatus.com has a searchable database of all Chrome features and upcoming APIs – super valuable stuff.
• https://github.com/privacycg/storage-access
• Extending Storage Access API (SAA) to non-cookie storage

cc @dmsnell