pixiv's "ugoira" animations don't load with https everywhere
Here's an example: http://www.pixiv.net/member_illust.php?mode=medium&illust_id=44298524 The image data for them is loaded using XHR from something like http://i2.pixiv.net/img-zip-ugoira/img/... Looks like pixiv redirects the CORS preflight back to http, which causes the browser to just give up. Tested on Firefox 47.0.1 and Chromium 51.0.2704.106 (both from Arch Linux packages).
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