1. The page crashes when a WebKitCSSKeyframeRule is dynamically modified.
  2. The bug is reproducable in Chrome 21.0.1180.57, and can be reproduced using the following code:
  3.  
  4. <style id="sheet">
  5. @-webkit-keyframes test {
  6. from {}
  7. }</style><script>
  8. var keyFramesRule = document.getElementById('sheet').sheet.cssRules[0];
  9. var keyFrameRule = keyFramesRule[0];
  10. keyFrameRule.style.top = 0;</script>
  11.  
  12. (Demo at http://jsfiddle.net/LVpWS/68/).
  13.  
  14. This crash does not happen when the property already exists in the rule. Replace from {} with from{top:1px;} to verify: http://jsfiddle.net/LVpWS/69/