[db48x]

Container Tabs are completely orthogonal. A site loaded in a tab which is contained in this way cannot access your global cookie jar, for example. If you visit a site with a Facebook Like button on it, then Facebook will not receive the same cookie from you that it would have received if you had loaded the site in a non–contained tab. This is true whether or not the site has been given it’s own process to live in. The converse is also still true; non–contained sites still have access to your global cookie jar even if they’re isolated in their own process.

Putting sites in their own process mitigates against Spectre–like attacks, but it doesn’t do anything for higher–level problems like third–party cookies.