Blob schemes won't load in iframes, even though blob:* is whitelisted.
This is needed for special cases, like when using an epub reader (ePub.js), that downloads an epub, extracts it to a blob and displays it in an iframe.
This currently works perfectly in cordova-android, but not in cordova-ios.
I've debugged why it happens... the Whitelists says the scheme is allowed and the URL is allowed, but then
returns false, thus cancelling the request. Hardcoding "blob" as an allowed scheme (like it's currently done with mailto, tel and sms) fixes this issue. I was about to put a pull request in github when I saw your contributing guidelines.