Echo, Flow, and a few other extensions use core's includes/utils/AutoloadGenerator.php to generate an autoload.php file that appends to $wgAutoloadClasses. As we convert to extension registration, this should be adapted to, e.g. load extension.json file, add the class map to its "AutoloadClasses" key, and write out the new extension.json.
Customize query in gerrit
Hi! Sorry I missed you on IRC. So I was imagining that AutoloadGenerator::generateAutoload() would check to see if a extension.json exists, and update it if that was the case. Otherwise it'll just update autoload.php if that file exists..