[whatwg] What is the purpose of timeupdate?

On Nov 6, 2009, at 1:44 AM, Philip J?genstedt wrote:

> We've considered firing it for each frame, but there is one problem.  
> If people expect that it fires once per frame they will probably  
> write scripts which do frame-based animations by moving things n  
> pixels per frame or similar. Some animations are just easier to do  
> this way, so there's no reason to think that people won't do it.  
> This will break horribly if a browser is ever forced to drop a  
> frame, which is going to happen on slower machines. In balance this  
> may or may not be a risk worth taking.
>
   I share Philip's concern.

eric