For some reason multiple backgrounds (gradient or image) cause animation jittering(due to constant repaint). It does not occur in Canary build and I tasted it in the incognito window so this is not extensions problem.
//sluggish
.two-bg {
-webkit-transition: 20s linear;
width: 640px;
height: 320px;
background-image:url("..."), url("...");
background-position: 0px 0px, 16px 16px;
}
//good
.single-bg {
-webkit-transition: 20s linear;
width: 640px;
height: 320px;
background-image:url("...");
}
.animate{
-webkit-transform: translateX(200%);
}
Demo: http://jsfiddle.net/8sWpr/1/
It's becomes real problem with the big paint rectangles.
