Reland "[headless] Use --disable-infobars switch in headless Chrome"

This is a reland of commit 70c02083

Replaced inline BUILDFLAG() reference that caused "code will never
be executed" error in CfT build with a traditional #if clause.

Original change's description:
> [headless] Use --disable-infobars switch in headless Chrome
>
> Disabling infobars in headless mode unconditionally has proven
> to be too aggressive. This CL changes infobars behavior in headless
> to be the same as in Chrome for Testing, which is: hide infobars
> only when --disable-infobars switch is present and only if the infobar
> has no buttons.
>
> Bug: 341947684, 333945848
> Change-Id: I8c544116d7650b3ebb7824406f328b6289494876
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5606442


> Commit-Queue: Peter Kasting <pkasting@chromium.org>
> Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
> Reviewed-by: Peter Kasting <pkasting@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1313099}

Bug: 341947684, 333945848
Change-Id: Id4efcbb466ee5c991f8551d22eb6664b0c0f42f5
Cq-Include-Trybots: luci.chromium.try:linux-rel-cft,mac-rel-cft,win-rel-cft
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5622293


Commit-Queue: Peter Kvitek <kvitekp@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1313670}