elliotcondon/acf — pull request #45 by kevinsperrine (2013-04-04 16:37:45+00:00)
Title: Added support for SSL asset loading.

WP_CONTENT_URL and WP_PLUGIN_URL do not take SSL into account, so if a user has forced loading the admin with SSL then Chrome will block loading the JS assets, because they're not being loaded from HTTPS; however, plugins_url() and content_url() both account for this.

http://core.trac.wordpress.org/ticket/13941