mozilla-release/dom/performance/tests/test_worker_performance_entries.html

<!-- Any copyright is dedicated to the Public Domain.
   - http://creativecommons.org/publicdomain/zero/1.0/ -->
<!DOCTYPE HTML>
<html>
<head>
  <title>PerformanceResouceTiming in workers</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<script class="testbody" type="text/javascript">

SimpleTest.waitForExplicitFinish();

// The worker assumes it will take some amount of time to load a resource.
// With a low enough precision, the duration to load a resource may clamp
// down to zero.
var reduceTimePrecisionPrevPrefValue = SpecialPowers.getBoolPref("privacy.reduceTimerPrecision");
SpecialPowers.setBoolPref("privacy.reduceTimerPrecision", false);

var worker = new Worker('test_worker_performance_entries.js');
worker.onmessage = function(event) {
  if (event.data.type == "check") {
    ok(event.data.status, event.data.msg);
    return;
  }

  if (event.data.type == "finish") {
    SpecialPowers.setBoolPref("privacy.reduceTimerPrecision", reduceTimePrecisionPrevPrefValue);
    SimpleTest.finish();
    return;
  }

  ok(false, "?!?");
}

</script>
</body>
</html>