[Partitioned Popins] (6) Add permissions policy for popin
This CL adds a permissions policy to control access to the partitioned
popin feature and sets the default to 'self'.
This series of CLs implement core components of the Partitioned Popin
system, significant additional effort will be needed to align with the
explainer and I2P, but all of that will depend on this work:
(1) Implement popin window feature
(2) popin feature triggers tab modal popup
(3) popin feature triggers third-party storage partitioning
(4) Renderer awareness of popin top-origin
(5) Limit window.opener access for popin
(6) Add permissions policy for popin
Explainer: https://explainers-by-googlers.github.io/partitioned-popins/
I2P: https://groups.google.com/a/chromium.org/g/blink-dev/c/ApU_zUmpQ2g/
Bug: 340606651
Change-Id: Ifde9f8e3529d794b5242df561603df7739a1f892
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5802591
Auto-Submit: Ari Chivukula arichiv@chromium.org
Reviewed-by: Daniel Cheng dcheng@chromium.org
Commit-Queue: Ari Chivukula arichiv@chromium.org
Cr-Commit-Position: refs/heads/main@{#1344862}