<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
@font-face {
    font-family: "AllAhem";
    src: url("AllAhem.svg") format("svg");
}

#test {
    font: 20px "AllAhem";
}
</style>
<script>
function runTest(testContent, localeString, lineBreakValue) {
    var container = document.getElementById("container");
    var test = document.getElementById("test");

    test.textContent = testContent;
    container.lang = localeString;
    container.style.webkitLineBreak = lineBreakValue;

    var current = 0;
    var breakpoints = [];
    var clientRectsLength = 2;
    for (var i = 1; clientRectsLength > 1; i += 5) {
        container.style.width = "" + i + "px";
        var width = test.getClientRects()[0].width;
        if (current != width) {
            current = width;
            breakpoints.push(width / 20);
        }
        clientRectsLength = test.getClientRects().length;
    }
    return breakpoints;
}
</script>
</head>
<body>
<div id="container" style="width: 99999999px;">
    <span id="test">Hello World</span>
</div>
</body>
</html>