Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/testing/web-platform/tests/paint-timing/resources/utils.js b/testing/web-platform/tests/paint-timing/resources/utils.js
new file mode 100644
index 0000000000..5766971dd0
--- /dev/null
+++ b/testing/web-platform/tests/paint-timing/resources/utils.js
@@ -0,0 +1,52 @@
+function waitForAnimationFrames(count) {
+  return new Promise(resolve => {
+    if (count-- <= 0) {
+      resolve();
+    } else {
+      requestAnimationFrame(() => {
+        waitForAnimationFrames(count).then(resolve);
+      });
+    }
+  });
+}
+
+// Asserts that there is currently no FCP reported. Pass t to add some wait, in case CSS is loaded
+// and FCP is incorrectly fired afterwards.
+async function assertNoFirstContentfulPaint(t) {
+  await waitForAnimationFrames(3);
+  assert_equals(performance.getEntriesByName('first-contentful-paint').length, 0, 'First contentful paint marked too early. ');
+}
+
+// Function that is resolved once FCP is reported, using PerformanceObserver. It rejects after a long
+// wait time so that failing tests don't timeout.
+async function assertFirstContentfulPaint(t) {
+  return new Promise(resolve  => {
+    function checkFCP() {
+      if (performance.getEntriesByName('first-contentful-paint').length === 1) {
+        resolve();
+      } else {
+        t.step_timeout(checkFCP, 0);
+      }
+    }
+    t.step(checkFCP);
+  });
+}
+
+async function test_fcp(label, before_assert_fcp_func) {
+  setup({"hide_test_state": true});
+  const style = document.createElement('style');
+  document.head.appendChild(style);
+  await promise_test(async t => {
+    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
+    const main = document.getElementById('main');
+    await new Promise(r => window.addEventListener('load', r));
+    await assertNoFirstContentfulPaint(t);
+    main.className = 'preFCP';
+    await assertNoFirstContentfulPaint(t);
+    if (before_assert_fcp_func) {
+      await before_assert_fcp_func();
+    }
+    main.className = 'contentful';
+    await assertFirstContentfulPaint(t);
+  }, label);
+}