Adds an onLoad event trigger for the iframe
Adds an onLoad event trigger for the iframe

- Checks if the content of the iframe could be loaded
- Checks the accessibility of the iframe content as well
- Prepares the check for the non loading X-FRAME options timeout

C3-TKO/junkan,C3-TKO/gaiyo,C3-TKO/junkan,C3-TKO/gaiyo