Add ORB test for sandboxed-frame (opaque origin).

This CL adds a test to confirm that ORB is active for opaque origins in
sandboxed iframes, where the opaque origin's precursor origin matches
the parent's origin. The test runs both with kIsolateSandboxedIframes
enabled and disabled.

Bug: 325432959
Change-Id: I08ada1455c1463e8065c2370ac769088c9f9ae1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5310615
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Commit-Queue: W. James Maclean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1263275}