UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

Steps to reproduce the problem:
Execute this code snippet in the console:

var a = function(){console.log('foo');}, b = null;
requestAnimationFrame(function() { cancelAnimationFrame(b); }); 
b = requestAnimationFrame(function () { a(); });

What is the expected behavior?
'foo' should be logged.

What went wrong?
'foo' is not logged to the console

Did this work before? N/A 

Chrome version: 71.0.3578.98  Channel: stable
OS Version: 10.0
Flash Version: 

Well, to be honest, I do not think chromium has a bug with this API. It works as I would expect. Problem is with firefox, but when I reported problem to them, I was told FF behaves according to the specification (https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#run-the-animation-frame-callbacks) and every other browser is not. So this ticket is meant to start a discussion and sync understanding of the specification.

Ideal result would be if chromium developers could convince firefox developers that their cancelAnimationFrame doesn't work properly.

Ticket on bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1509466