Re: [whatwg] Fullscreen API and out-of-process <iframe>


1) The frames attempt no synchronization and both just call
requestFullscreen(). In that case, the observable difference is largely
moot. It shouldn't be surprising that racing operations like this cross
origin returns a non-deterministic result. This is the position the Chrome
out-of-process team is taking for other sorts of actions that have effects
visible outside the frame (for example, navigating the top level frame,
multiple frames sending a postMessage to the same frame, etc).

2) One frame calls requestFullscreen() and then sends a postMessage() to
another frame, which calls requestFullscreen() upon receiving the message.
Going fullscreen requires coordination with the browser process, so
ordering is preserved by browser IPC message handling.


On Mon, Jul 28, 2014 at 11:56 PM, Anne van Kesteren <>

> On Mon, Jul 28, 2014 at 8:16 PM, Adam Barth <> wrote:
> > I meant a black-box experiment (i.e., no access to browser internal
> state).
> > Put another way, can you describe a sequence of events in which the
> author
> > or the user could observe the difference?  If not, then the question is
> > moot.
> Well if both A and B invoke requestFullscreen() that's obviously for
> different elements. The observable difference would be which element
> ends up being fullscreen of course and which call would either fail or
> end up overwriting the other depending on how we decide to deal with
> this.
> --

Received on Tuesday, 29 July 2014 07:52:17 UTC