Starting in December of 2019 (Chrome 79) Google Chrome will introduce a feature flag (defaulted to off) to disallow all mixed content. It will attempt to upgrade resources to HTTPS if they happen to also exist. In future releases by Google Chrome the mixed content will simply not be loaded.
It’s a poor user experience to have mixed content as well as it not being as safe or secure to the user. Mixed content should be addressed as soon as possible to avoid potential disruptions, should any exist.
More information about this change can be found at: https://blog.chromium.org/2019/10/no-more-mixed-messages-about-https.html