LayoutTests/fast/canvas/canvas-inside-viewport-timer-throttling.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <head>
 <script src="../../resources/js-test-pre.js"></script>
 <script>
 var i = 0;
 var context;
 var timeoutId;

 function loop()
 {
    i = (i + 1) % 255;
    context.fillStyle = "rgb(" + i + ", 0, 0)";
    context.fillRect(0, 0, 150, 150);

    // 5 iterations should suffice to throttle the timer.
    if (i == 5) {
      debug("Timer should still not be throttled because it is drawing on a canvas inside viewport.");
      shouldBeFalse("internals.isTimerThrottled(timeoutId)");
      clearInterval(timeoutId);
      finishJSTest();
    }
 }

 function runTest() {
   context = document.getElementById("canvas").getContext('2d');

   timeoutId = setInterval(loop, 5);
   debug("Timer should initially not be throttled.");
   shouldBeFalse("internals.isTimerThrottled(timeoutId)");
 }
 </script>
 </head>
 <body onload="runTest();">
 <script>
 description("Test that a DOM timer drawing on a canvas inside viewport does not get throttled.");
 jsTestIsAsync = true;
 </script>
 <canvas id="canvas" width=150 height=150></canvas>
 <script src="../../resources/js-test-post.js"></script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<script src="../../resources/js-test-pre.js"></script>
	<script>
	var i = 0;
	var context;
	var timeoutId;

	function loop()
	{
	i = (i + 1) % 255;
	context.fillStyle = "rgb(" + i + ", 0, 0)";
	context.fillRect(0, 0, 150, 150);

	// 5 iterations should suffice to throttle the timer.
	if (i == 5) {
	debug("Timer should still not be throttled because it is drawing on a canvas inside viewport.");
	shouldBeFalse("internals.isTimerThrottled(timeoutId)");
	clearInterval(timeoutId);
	finishJSTest();
	}
	}

	function runTest() {
	context = document.getElementById("canvas").getContext('2d');

	timeoutId = setInterval(loop, 5);
	debug("Timer should initially not be throttled.");
	shouldBeFalse("internals.isTimerThrottled(timeoutId)");
	}
	</script>
	</head>
	<body onload="runTest();">
	<script>
	description("Test that a DOM timer drawing on a canvas inside viewport does not get throttled.");
	jsTestIsAsync = true;
	</script>
	<canvas id="canvas" width=150 height=150></canvas>
	<script src="../../resources/js-test-post.js"></script>
	</body>
	</html>