What does the code in 'wp-admin-bar-css.php' do (BP Social Theme)

I found this code in 'bp-admin-bar-css.php'
Wanted to know what this code do?

====================================================================

function buddypress_global_adminbar_css() {
// only work for wpmudev buddypress theme with theme options
global $current_site, $blog_id; ?>

<?php // save site options
if($blog_id == BP_ROOT_BLOG) {
$active_themename = get_option('template');
$check_if_theme_save = get_site_option('blog_1_active_theme');
if($check_if_theme_save == '') {
add_site_option('blog_1_active_theme', $active_themename);
} else {
update_site_option('blog_1_active_theme', $active_themename);
}
}
?>

<?php $main_blog_active_theme = get_site_option('blog_1_active_theme'); // styling global started here ?>
<link rel="stylesheet" target="_blank" href="http://<?php echo $current_site->domain . $current_site->path . 'wp-content/themes/' . $main_blog_active_theme .'/global-adminbar.php'; ?>" type="text/css" media="screen" />
<?php }

add_action('wp_head', 'buddypress_global_adminbar_css'); // init global wp_head
add_action('admin_head', 'buddypress_global_adminbar_css'); // init global admin_head

====================================================================

The simple answer I would like to know is:
Is this code responsible for calling "wp-admin-bar.css" in the header of all the themes?
If no, can you tell me where is wp-admin-bar.css registered?

Actually, I do not need that file to be called in every theme on its own, so want to remove it.
Any help would be appreciated.