[whatwg] Simplified <picture> element draft

[Boris Zbarsky]

On 1/7/14 12:01 PM, Yoav Weiss wrote:
> I'd love to get some more details regarding that. I'll start a
> mozilla.dev.platform thread on the subject, since it's Gecko specific.

It's actually not entirely Gecko-specific.

Consider a display:none iframe.  How should viewport-size-related media 
queries be evaluated in such a thing?  The specs don't define it, as far 
as I can tell.  In fact, the specs don't actually define anything useful 
for the viewport of a framed document at all, as far as I can see.  CSS 
just assumes a viewport exists, and HTML doesn't define anything about 
frames setting up a viewport for the document inside them...

But say they defined it.  How would the viewport of a display:none 
iframe be defined, exactly?

Last I checked, UAs just end up doing wildly different things in this 
situation.

-Boris