Mozillians who can provide input (optional): @dveditz
Other information
We already implement Mixed Content 1. The newest bits are automated upgrading of subresources that are not already blocked by default (e.g., not scripts). The spec also introduces blocking of "mixed downloads", which AFAIU we also implement.
Implementing this would increase HTTPS adoption and would set us on a clearer path for potential future work in the realm of HTTPS-First/HTTPS-Only.
Request for Mozilla Position on an Emerging Web Specification
Other information
We already implement Mixed Content 1. The newest bits are automated upgrading of subresources that are not already blocked by default (e.g., not scripts). The spec also introduces blocking of "mixed downloads", which AFAIU we also implement.
Implementing this would increase HTTPS adoption and would set us on a clearer path for potential future work in the realm of HTTPS-First/HTTPS-Only.