Firefox IntersectionObserver in iframes

[serbel]

When the OVV library starts in the iframe which nested in another crossdomain iframe, it is necessary to initiate IntersectionObserver through the parent element, e.g. "element.ownerDocument.defaultView", otherwise the element will always be invisible.

[jdreetz]

@serbel - I can't reproduce this issue on Firefox for Mac with the latest version. Can you share a test page that duplicates the issue and specify which version of Firefox you were using?

Thanks,