Google on their Security Blog published
Protecting users from insecure downloads in Google Chrome
Today we’re announcing that Chrome will gradually ensure that secure (HTTPS) pages only download secure files. In a series of steps outlined below, we’ll start blocking “mixed content downloads” (non-HTTPS downloads started on secure pages). This move follows a plan we announced last year to start blocking all insecure subresources on secure pages.
with a schedule table
if you are mixing HTTP with HTTPS and suddenly in the future some things get blocked that will be because of that