Question

This can be tested here: http://jsfiddle.net/rGECn/2/

Is there a workaround for this issue available?

UPDATE 1:

transitionend in window returns false.

Answer 1

You’re missing some vendor prefixes in the CSS.

button {
    width: 100px;
    -moz-transition: all 1s;
    -o-transition: all 1s;
    -webkit-transition: all 1s;
    transition: all 1s;
}

According to this compat table, transitions are only supported in IE10 so I’d suggest using jQuery’s animate method for a cross-browser solution:

$('button').click(function() {
    var toggle = [100, 150],
        $this = $(this),
        c = $this.data('count') + 1;
    $this.data('count', c);
    $this.stop(true).animate({'width': toggle[c % toggle.length]}, 1000, function() {
        //done callback
        count();
    });
}).data('count', 0);

Fiddle

Remove the .stop(true) if you want to queue up animations instead of breaking them when users click while it is animating.