Modernize WPT: resource-timing and navigation-timing.https.html

As a part of the effort to understand the current behavior of the
resource timing, I changed the tests to use async/await for readability
with adding a few comments.

Bug: 1128786
Change-Id: I45daee67e52a13c98ad3f2010131d858a58781d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2413927
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Auto-Submit: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807845}

third_party/blink/web_tests/external/wpt/service-workers/service-worker/navigation-timing.https.html

@@ -32,81 +32,45 @@ function navigate_in_frame(frame, url) {
 
 const worker_url = 'resources/navigation-timing-worker.js';
 
-promise_test(t => {
+promise_test(async (t) => {
     const scope = 'resources/empty.html';
-    let frame;
+    const registration = await service_worker_unregister_and_register(t, worker_url, scope);
+    t.add_cleanup(() => registration.unregister());
+    await wait_for_state(t, registration.installing, 'activated');
+    const frame = await with_iframe(scope);
+    t.add_cleanup(() => frame.remove());
 
-    return service_worker_unregister_and_register(t, worker_url, scope)
-      .then(r => {
-        return wait_for_state(t, r.installing, 'activated');
-      })
-      .then(() => with_iframe(scope))
-      .then(f => {
-        frame = f;
-        return navigate_in_frame(frame, 'resources/empty.html');
-      })
-      .then(timing => {
-        assert_greater_than(timing.workerStart, 0);
-        verify(timing);
-      })
-      .catch(unreached_rejection(t))
-      .then(() => {
-        if (frame)
-            frame.remove();
-        return service_worker_unregister(t, scope);
-      });
+    const timing = await navigate_in_frame(frame, scope);
+    assert_greater_than(timing.workerStart, 0);
+    verify(timing);
 }, 'Service worker controlled navigation timing');
 
-promise_test(t => {
+promise_test(async (t) => {
     const scope = 'resources/empty.html?network-fallback';
-    let frame;
+    const registration = await service_worker_unregister_and_register(t, worker_url, scope);
+    t.add_cleanup(() => registration.unregister());
+    await wait_for_state(t, registration.installing, 'activated');
+    const frame = await with_iframe(scope);
+    t.add_cleanup(() => frame.remove());
 
-    return service_worker_unregister_and_register(t, worker_url, scope)
-      .then(r => {
-        return wait_for_state(t, r.installing, 'activated');
-      })
-      .then(() => with_iframe(scope))
-      .then(f => {
-        frame = f;
-        return navigate_in_frame(frame, 'resources/empty.html?network-fallback');
-      })
-      .then(timing => {
-        verify(timing);
-      })
-      .catch(unreached_rejection(t))
-      .then(() => {
-        if (frame)
-            frame.remove();
-        return service_worker_unregister(t, scope);
-      });
+    const timing = await navigate_in_frame(frame, scope);
+    verify(timing);
 }, 'Service worker controlled navigation timing network fallback');
 
-promise_test(t => {
+promise_test(async (t) => {
     const scope = 'resources/redirect.py?Redirect=empty.html';
-    let frame;
+    const registration = await service_worker_unregister_and_register(t, worker_url, scope);
+    t.add_cleanup(() => registration.unregister());
+    await wait_for_state(t, registration.installing, 'activated');
+    const frame = await with_iframe(scope);
+    t.add_cleanup(() => frame.remove());
 
-    return service_worker_unregister_and_register(t, worker_url, scope)
-      .then(r => {
-        return wait_for_state(t, r.installing, 'activated');
-      })
-      .then(() => with_iframe(scope))
-      .then(f => {
-        frame = f;
-        return navigate_in_frame(frame, 'resources/redirect.py?Redirect=empty.html');
-      })
-      .then(timing => {
-        verify(timing);
-        // Additional checks for redirected navigation.
-        assert_true(timing.redirectStart <= timing.redirectEnd,
-            'Expected redirectStart <= redirectEnd');
-        assert_true(timing.redirectEnd <= timing.fetchStart,
-            'Expected redirectEnd <= fetchStart');
-      })
-      .catch(unreached_rejection(t))
-      .then(() => {
-        if (frame)
-            frame.remove();
-        return service_worker_unregister(t, scope);
-      });
+    const timing = await navigate_in_frame(frame, scope);
+    verify(timing);
+    // Additional checks for redirected navigation.
+    assert_true(timing.redirectStart <= timing.redirectEnd,
+        'Expected redirectStart <= redirectEnd');
+    assert_true(timing.redirectEnd <= timing.fetchStart,
+        'Expected redirectEnd <= fetchStart');
 }, 'Service worker controlled navigation timing redirect');
 </script>