<!doctype html>
<!--
Copyright 2016 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<html style="height:100%">
<head>
<style>
html, body {
margin: 0;
padding: 0;
}
</style>
</head>
<body style="height:100%">
<canvas id="canvas" width="200" height="100"></canvas>
</body>
<script>
var canvas = document.querySelector('canvas');
canvas.style.width ='100%';
canvas.style.height='100%';
canvas.width = canvas.offsetWidth;
canvas.height = canvas.offsetHeight;
var ctx = canvas.getContext("2d");
var rColor = 0;
function animate() {
rColor += 1;
rColor %= 255;
ctx.fillStyle = 'rgb(' + rColor + ',0,0)';
ctx.fillRect(0, 0, canvas.width, canvas.height);
window.requestAnimationFrame(animate);
}
window.onload = animate;
</script>
</html>