Chrome recently flipped the default headless mode of `--headless`

[mdmintz]

Chrome recently flipped the default headless mode of --headless

There were details in https://developer.chrome.com/docs/chromium/headless about it.

When Chrome's newer headless mode came out, it was initialized via --headless=new.
They also renamed the old Chrome headless mode initiation to --headless=old, and for awhile, --headless pointed to that.

Now, --headless points to --headless=new in the options of Chromium 129, so there needs to be a way to use the old headless mode. Although the older headless mode is going to be phased out soon, it still works for the time being, and is actually a bit faster than the newer headless mode (although the newer headless mode more accurately represents how a real headed browser behaves, with some differences such as headless appearing in the User Agent string, etc).

I'll add a --headless1 option in SeleniumBase, which will initialize Chrome's old headless mode via --headless=old.
(At some point, Chrome may remove that old headless mode.)

There currently already exists:

• --headless, which sets --headless as a Chrome option. (Depending on the Chrome version, it could be old or new.)
• --headless2, which sets --headless=new as a Chrome option.

(If the backend is the same for all Chromium browsers, I'll also add --headless1 as a SeleniumBase Edge option.)

[mdmintz]

This was resolved in 4.31.1 - https://github.com/seleniumbase/SeleniumBase/releases/tag/v4.31.1