1 files changed, 46 insertions, 0 deletions
diff --git a/testing/web-platform/tests/paint-timing/with-first-paint/child-painting-first-image.html b/testing/web-platform/tests/paint-timing/with-first-paint/child-painting-first-image.html
new file mode 100644
index 0000000000..92a926a2b9
--- /dev/null
+++ b/testing/web-platform/tests/paint-timing/with-first-paint/child-painting-first-image.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<body>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+var entriesExpectToReceive = [
+    {
+        'entryType': 'paint',
+        'name': 'first-paint'
+    },
+    {
+        'entryType': 'paint',
+        'name': 'first-contentful-paint'
+    }
+];
+
+setup({"hide_test_state": true});
+async_test(function (t) {
+    assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported.");
+    window.addEventListener('message', t.step_func(e => {
+        // When only child frame paints, expect only first-paint.
+        for (let i = 0; i < entriesExpectToReceive.length; i++) {
+            if (entriesExpectToReceive[i].entryType == e.data.entryType &&
+                entriesExpectToReceive[i].name == e.data.name) {
+                entriesExpectToReceive.splice(i, 1);
+                break;
+            }
+        }
+
+        if (entriesExpectToReceive.length == 0) {
+            const bufferedEntries = performance.getEntriesByType('paint');
+            assert_equals(bufferedEntries.length, 1);
+            assert_equals(bufferedEntries[0].entryType, 'paint');
+            assert_equals(bufferedEntries[0].name, 'first-paint');
+            t.done();
+        }
+    }));
+    const iframe = document.createElement('iframe');
+    iframe.id = 'child-iframe';
+    iframe.src = '../resources/subframe-painting.html';
+    document.body.appendChild(iframe);
+}, 'Parent frame ignores paint-timing events fired from child image rendering.');
+</script>
+</body>
+</html>