<style>
div {
    width: 10px;
    height: 10px;
    background-color: green;
}
</style>
<div id="test1" style="clip: rect(auto, auto, auto, auto);">
<div id="test2" style="clip: rect(5px, auto, auto, auto);">
<div id="test3" style="clip: rect(auto, 5px, auto, auto);">
<div id="test4" style="clip: rect(auto, auto, 5px, auto);">
<div id="test5" style="clip: rect(auto, auto, auto, 5px);">
<div id="test6" style="clip: rect(5px, auto, 5px, auto);">

<script>

if (window.testRunner)
    testRunner.dumpAsText();

function outputStyleForElement(id) {
    var element = document.getElementById(id);
    var clipStyle = getComputedStyle(element).clip;
    var p = document.createElement("p");
    p.innerText = clipStyle;
    document.body.appendChild(p);
}

outputStyleForElement("test1");
outputStyleForElement("test2");
outputStyleForElement("test3");
outputStyleForElement("test4");
outputStyleForElement("test5");
outputStyleForElement("test6");
</script>