Google Chrome will soon restrict certain files, like PDFs or executables, from being downloaded via an HTTP connection, if they are loaded on HTTPS webpages. HTTPS websites can still serve up images, scripts or other file types that are downloaded using the less-secure HTTP connection. Google wants to uproot this issue by first warning users of, and later blocking, mixed content downloads, over HTTP, which could consist of HTTP executables (such as.zip oriso files) and all other non-safe types. Google: “Insecurely downloaded programs can be swapped out for malware by attackers”””
Source: https://threatpost.com/google-chrome-to-bar-http-file-downloads/152674/