I think the root issue in that we are committing CSS on all children. We've yet to come up with a more efficient way of computing the outline of an element but we're open to ideas. Potentially we could drop the shields and only compute outlines on focus. I believe we only need the shields for IE which doesn't respect contenteditable=false.

On 15 May 2014 23:58, "Jon Robson" <jrobson@wikimedia.org> wrote:
I'm still waiting for Kaldari or someone in mobile to merge
https://gerrit.wikimedia.org/r/131892 before I can confirm the current
state.

It definitely seems to be marginally improved on desktop and mobile
(with desktop benefiting most) after a few runs.

For the record the nasty page I'm testing on is
http://en.m.wikipedia.beta.wmflabs.org/wiki/Jon%27s_nasty_VE_test_page?mobileaction=alpha

On Thu, May 15, 2014 at 7:44 PM, Roan Kattouw <rkattouw@wikimedia.org> wrote:
> On May 15, 2014 10:27 AM, "Roan Kattouw" <rkattouw@wikimedia.org> wrote:
>> Ed has been fixing some things to do with shields and phantoms. I'll send
>> you some Gerrit links in a minute.
>>
> https://gerrit.wikimedia.org/r/#/c/133236/
>
> https://gerrit.wikimedia.org/r/#/c/130823/
>
> The former should address the importNode problem Jon mentioned and the
> latter should improve CSS performance, as it addresses something similar to
> a problem in MF that Jon reported.
>
> As James said, new performance feedback after these changes (though in
> fairness one of them was merged only this week) would be helpful. We think
> we've quashed most of the things Jon flagged initially, but we may not have
> done so adequately or new problems may now be surfacing.
>
> Roan