[whatwg] Proposal: Make about:srcdoc resolvable on iframes containing a @srcdoc.

[Justin Schuh]

Currently, section 2.5.1 states that about:srcdoc should not be navigable:

    "This specification defines the URL about:srcdoc as a reserved, though
     unresolvable, about: URI, that is used as the document's address of iframe
     srcdoc documents."

In working on the WebKit implementation I've found that this
requirement would necessitate major changes to the navigation and
document loading implementation. Additionally, I do think there should
be a simple method of navigating to the iframe's srcdoc browsing
context. (As currently described, this can be triggered only by
modifying @srcdoc from an outer, same origin browsing context.)

So, I propose making about:srcdoc resolvable when the srcdoc attribute
is present on the iframe. It should be unresolvable only when
navigated to on a browsing context that is not an iframe with @srcdoc
set.

Regards,
Justin Schuh