LayoutTests/fast/canvas/toDataURL-alpha.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <title>canvas toDataURL alpha png bug</title>
 <script type="text/javascript">
 if (window.testRunner)
   testRunner.dumpAsText(true);

   function load() {
       var context = document.getElementById("c").getContext("2d");
       context.fillStyle = "rgba(200, 255, 200, 0.7)";
       context.fillRect(0, 0, context.canvas.width, context.canvas.height);
       document.getElementById("d").style.backgroundImage = ["url(", context.canvas.toDataURL("image/png"), ")"].join("");
   }
 </script>
 </head>
 <body onload="load()">
     <p>The test passes if both boxes below have the same color.</p>
     <canvas id="c" width="200" height="100"></canvas>
     <div id="d" style="width:200px;height:100px"></div>
 </body>
 </html>
	<!DOCTYPE html>
	<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
	<title>canvas toDataURL alpha png bug</title>
	<script type="text/javascript">
	if (window.testRunner)
	testRunner.dumpAsText(true);

	function load() {
	var context = document.getElementById("c").getContext("2d");
	context.fillStyle = "rgba(200, 255, 200, 0.7)";
	context.fillRect(0, 0, context.canvas.width, context.canvas.height);
	document.getElementById("d").style.backgroundImage = ["url(", context.canvas.toDataURL("image/png"), ")"].join("");
	}
	</script>
	</head>
	<body onload="load()">
	<p>The test passes if both boxes below have the same color.</p>
	<canvas id="c" width="200" height="100"></canvas>
	<div id="d" style="width:200px;height:100px"></div>
	</body>
	</html>