[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}