When discussing the HTTP -> HTTPS migration of credentials it was mentioned that it is beneficial to remove old HTTP credentials during the migration when a site switches to HTTPS with HSTS active.
In addition, obsolete HTTP passwords should be cleaned up for HSTS sites, regardless of whether a migration takes place.
It is the purpose of this bug to track efforts towards implementing this feature.
Comment 1 by bugdroid1@chromium.org
, Feb 2 2017