This follows the rules as defined in
https://w3c.github.io/webappsec-csp/#security-inherit-csp
where local iframes (about:blank and about:srcdoc) should
initially start with the CSP rules of the parent. After
that, all new CSP headers should only be set on the
policy container of the iframe.
Part of #36437
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
Also update a WPT test to fail-fast if the iframe incorrectly
evaluates the `eval`. Before, it would run into a timeout if
the implementation is correct. Now we reject the promise
when an exception is thrown.
Requires servo/rust-content-security-policy#6
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>