[resize-observer] The monkey patching of the event loop processing model appears to be outdated #4824
Description
The entire section about HTML event loop processing model appears to be outdated.
I think this section is trying to monkey patch step 14 of updating the rendering step in the current processing model.
The spec also mentions steps like "recall styles" and "update layout". Since these aren't concepts formally defined anywhere, it's probably best to consolidate as a single step to generate or update the CSS boxes and their geometry or something instead too.