LayoutTests/fast/dom/timer-throttling-background-page-near-alignment-interval.html - experimental/chromium/blink - Git at Google

 <html>
 <head>
     <script src="../../resources/js-test.js"></script>
     <script>
         description('<a href="http://crbug.com/259680">Bug 259680</a>: JavaScript setInterval lagging behind');

         var jsTestIsAsync = true;
         var intervalDuration = 1000;
         var testDuration = 4000;
         var expectedNumFires = 4;
         var numFires = 0;
         var tolerance = 1;

         var intervalID;
         var startTime;

         function timerFired()
         {
             ++numFires;

             var currentTime = new Date().getTime();
             if (currentTime >= startTime + testDuration) {
                 shouldBeCloseTo("numFires", expectedNumFires, tolerance);

                 clearInterval(intervalID);
                 finishJSTest();
                 return;
             }
         }

         function runTest()
         {
             if (!window.testRunner) {
                 debug('This test requires testRunner');
                 return;
             }

             testRunner.dumpAsText();

             testRunner.setPageVisibility("hidden");
             startTime = new Date().getTime();
             intervalID = window.setInterval(timerFired, intervalDuration);
         }
     </script>
 </head>
 <body onload="runTest()">
     <p>
     This test ensures that intervals on background pages whose duration is close to the timer alignment interval don't miss every other firing.
     </p>
 </body>
 </html>
	<html>
	<head>
	<script src="../../resources/js-test.js"></script>
	<script>
	description('<a href="http://crbug.com/259680">Bug 259680</a>: JavaScript setInterval lagging behind');

	var jsTestIsAsync = true;
	var intervalDuration = 1000;
	var testDuration = 4000;
	var expectedNumFires = 4;
	var numFires = 0;
	var tolerance = 1;

	var intervalID;
	var startTime;

	function timerFired()
	{
	++numFires;

	var currentTime = new Date().getTime();
	if (currentTime >= startTime + testDuration) {
	shouldBeCloseTo("numFires", expectedNumFires, tolerance);

	clearInterval(intervalID);
	finishJSTest();
	return;
	}
	}

	function runTest()
	{
	if (!window.testRunner) {
	debug('This test requires testRunner');
	return;
	}

	testRunner.dumpAsText();

	testRunner.setPageVisibility("hidden");
	startTime = new Date().getTime();
	intervalID = window.setInterval(timerFired, intervalDuration);
	}
	</script>
	</head>
	<body onload="runTest()">
	<p>
	This test ensures that intervals on background pages whose duration is close to the timer alignment interval don't miss every other firing.
	</p>
	</body>
	</html>