Add mystery conditional into updateCMSNam() that was present in Drupal 7.
Tidy up comments.
Update CRM_Utils_System_Drupal8::getLoginURL() to Drupal 8.
Provide a few comments for CRM_Utils_System_Drupal8::addHTMLHead().
Consolidate url path and query string extraction and internal route algorithm.
Handle Civicrm setting breadcrumbs.