[PSA]: Chrome for Testing has third-party cookies blocked by default

[Giovanni Ortuño]

Third-party cookies have been blocked by default in Chrome for Testing, a Chrome variant that targets web app testing and automation use cases, since version 121.0.6143.0 which shipped to Stable on January 23, 2024.

Third-party cookie blocking can be disabled by using the command-line flag `--disable-features=TrackingProtection3pcd` when launching Chrome for Testing.

This was implemented as part of the previous plans to restrict third-party cookies by default and will still continue as Chrome moves toward a new path that elevates user choice.

We plan to keep this default configuration in Chrome for Testing because, (1) it makes automated testing more consistent with other browsers which block third-party cookies by default, and (2) avoids breaking developers who now rely on the default configuration.

Thanks,

Gio