CSS3动画在Windows Safari中不起作用

Question

CSS3动画在safari中无法正常工作，并且在所有其他浏览器中都能正常工作。

操作系统：Windows

HTML

<img src='../images/image1.png' class='test' />

CSS

   .test {
      animation: test 2s ease;
      -webkit-animation: test 2s ease; 
   }

   @keyframes test {
        0%, 20%, 40%, 60%, 80%, 100% {
            content: url('../images/image2.png');
        }

        10%, 30%, 50%, 70%, 90% {
            content: url('../images/image1.png');
        }
    }

    @-webkit-keyframes test {
        0%, 20%, 40%, 60%, 80%, 100% {
            content: url('../images/image2.png');            
        }

        10%, 30%, 50%, 70%, 90% {
            content: url('../images/image1.png');
        }
    }