Change Details

Now that Echo is using OOUI server-side on all pages, and loading the 'oojs-ui.styles' module on all pages (by calling OutputPage::enableOOUI() from BeforePageDisplay hook), I think it's become more necessary to split OOjs UI's distribution .css files into code required by PHP version, and required by JS only. `mw.loader.inspect()` tells me that the 'oojs-ui.styles' module is 95.8 kB currently, making it the third biggest loaded on all pages (after 'oojs-ui' and 'oojs-ui.styles.icons'). This is even worse because due to T87871 this is loaded twice.