TemplateStyles could really use this, since people object to e.g. the TemplateStyles CSS being able to mess with the diff tables. I posted an analysis and some options at https://phabricator.wikimedia.org/T37247#3181097. Feedback would be appreciated, particularly from someone familiar with how exactly content gets into VE and Flow as to what if anything else might be needed to get the new div to be output in those extensions.

Thanks.