first-contentful-canvas-webgl2.html

Enable keyboard shortcuts

This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /paint-timing/with-first-paint/first-contentful-canvas-webgl2.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<head>

  <title>Performance Paint Timing Test: FCP due to canvas</title>

</head>

<body>

  <script src="/resources/testharness.js"></script>

  <script src="/resources/testharnessreport.js"></script>

  <canvas id="canvas" width="200" height="200"></canvas>

  <script>

    setup({ "hide_test_state": true });

    async_test(function (t) {

      assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");

      const canvas = document.getElementById("canvas");

      const context = canvas.getContext("webgl2");

      if (!context) {

        assert_implements_optional(context, "WebGL 2 Canvas isn't supported.")

      context.clearColor(0.3, 0.3, 0.3, 1);

      context.clear(context.COLOR_BUFFER_BIT);

      function testPaintEntries() {

        const bufferedEntries = performance.getEntriesByType('paint');

        if (bufferedEntries.length < 2) {

          t.step_timeout(function () {

            testPaintEntries();

          }, 20);

          return;

        t.step(function () {

          assert_equals(bufferedEntries.length, 2, "There should be two paint timing instances.");

          assert_equals(bufferedEntries[0].entryType, "paint");

          assert_equals(bufferedEntries[0].name, "first-paint");

          assert_equals(bufferedEntries[1].entryType, "paint");

          assert_equals(bufferedEntries[1].name, "first-contentful-paint");

          t.done();

});

};

      t.step(function () {

        testPaintEntries();

});

    }, "First contentful paint fires due to webgl2 canvas render.");

  </script>

</body>

</html>