diff --git a/client-hints/resources/sec-ch-ua.py b/client-hints/resources/sec-ch-ua.py
index a14a27dadf9e33..f77eee8c4e9b13 100644
--- a/client-hints/resources/sec-ch-ua.py
+++ b/client-hints/resources/sec-ch-ua.py
@@ -5,7 +5,7 @@ def main(request, response):
     response.headers.set("Accept-CH-Lifetime", "10")
     response.content = '''
 <script>
-  window.opener.postMessage({ header: "%s" }, "*");
+  window.opener.postMessage({ header: '%s' }, "*");
 </script>
 Sec-CH-UA: %s
 ''' % (ua, ua)
diff --git a/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.https.html b/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.https.html
new file mode 100644
index 00000000000000..4c83c7e8a546dd
--- /dev/null
+++ b/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.https.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/webrtc/dictionary-helper.js"></script>
+<script>
+  test(t => {
+    assert_true("userAgentData" in navigator);
+  }, "navigator.getUserAgent() is exposed.");
+
+  promise_test(async t => {
+    const uaData = navigator.userAgentData;
+    for (ua of uaData.uaList) {
+      assert_equals(typeof ua.brand, "string", "brand should be a string");
+      assert_equals(typeof ua.version, "string", "version should be a string");
+    }
+    assert_equals(typeof uaData.mobile, "boolean", "mobile should be a boolean");
+    const highEntropyData = await uaData.getHighEntropyValues(["platform", "platformVersion", "architecture", "model"]);
+    assert_equals(typeof highEntropyData["platform"], "string", "Platform brand should be a string");
+    assert_equals(typeof highEntropyData["platformVersion"], "string", "Platform version should be a string");
+    assert_equals(typeof highEntropyData["architecture"], "string", "Architecture should be a string");
+    assert_equals(typeof highEntropyData["model"], "string", "Model should be a string");
+    const highEntropyData2 = await uaData.getHighEntropyValues([]);
+    assert_equals(highEntropyData2["platform"], "", "Platform brand should be an empty string");
+    assert_equals(highEntropyData2["platformVersion"], "", "Platform version should be an empty string");
+    assert_equals(highEntropyData2["architecture"], "", "Architecture should be an empty string");
+    assert_equals(highEntropyData2["model"], "", "Model should be an empty string");
+  }, "navigator.getUserAgent() returns a UserAgentMetadata object.");
+</script>
diff --git a/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.tentative.https.html b/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.tentative.https.html
deleted file mode 100644
index 5f0dba6bcf72cb..00000000000000
--- a/html/webappapis/system-state-and-capabilities/the-navigator-object/navigator_user_agent.tentative.https.html
+++ /dev/null
@@ -1,21 +0,0 @@
-<!DOCTYPE html>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/webrtc/dictionary-helper.js"></script>
-<script>
-  test(t => {
-    assert_true("getUserAgent" in navigator);
-  }, "navigator.getUserAgent() is exposed.");
-
-  promise_test(t => {
-    return navigator.getUserAgent()
-      .then(ua => {
-        // TODO(web-platform-tests/wpt#9106): Use `idlharness.js` once it supports dictionaries.
-        assert_string_field(ua, "brand");
-        assert_string_field(ua, "version");
-        assert_string_field(ua, "platform");
-        assert_string_field(ua, "architecture");
-        assert_string_field(ua, "model");
-      });
-  }, "navigator.getUserAgent() returns a UserAgentMetadata object.");
-</script>
