css3 background-size transition animation in Webkit doesn't work... Bug? Or wrong syntax?

Question

Animating the background-size property doesn't seem to be working in Chrome or Safari.

div {
    width: 161px;
    height: 149px;
    background: url(http://3.bp.blogspot.com/_HGPPifzMEZU/Rw4ujF12G3I/AAAAAAAAAWI/bc1ppSb6eKA/s320/estrelas_09.gif) no-repeat center center;
    background-size: 50% 50%;
    transition: background-size 2s ease-in;
    -moz-transition: background-size 2s ease-in;
    -web-kit-transition: background-size 2s ease-in
}
div:hover {
    background-size: 100% 100%
}

<div>
hey
</div>

http://jsfiddle.net/ubcka/14/

Answer 1

It's not widely supported. See a complete list of CSS properties that support transition here. I would have a different approach. Wrap your element with background-color you wanted to do transition to, and do a scale transition for your element.

<div class="your-wrapper">
  <div class="your-div">

  </div>   
</div>

also make sure to add proper styling

.your-wrapper {
   overflow:hidden
}
.your-div {
   transition: transform 0.5s; 
   -webkit-transition: -webkit-transform 0.5s
}
.your-wrapper:hover .your-div{
   transform: scale(1.5); -webkit-transform: scale(1.5);
}

This should do.