Created attachment 437644 [details] Testcase Load events are not fired for <embed> elements. I've only tested with an embedded PDF, but this may be true for other types of embedded objects too. According to the spec, load events should be fired for <embed> elements: https://html.spec.whatwg.org/multipage/iframe-embed-object.html#display-a-plugin Testcase is attached — update the src path to a PDF on your machine.
<rdar://problem/83156577>