Update web-platform-tests and CSS tests.

- Update CSS tests to revision e05bfd5e30ed662c2f8a353577003f8eed230180.
- Update web-platform-tests to revision a052787dd5c069a340031011196b73affbd68cd9.

tests/wpt/web-platform-tests/notifications/resources/shownotification-sw.js

@@ -0,0 +1,27 @@
+self.onmessage = event => {
+  // Checking for a particular value, so more tests can be added in future.
+  if (event.data !== 'test-shownotification') return;
+
+  // Random number, so we can identify the notification we create.
+  const random = Math.random().toString();
+  const start = Date.now();
+
+  event.waitUntil(
+    self.registration.showNotification('test', {
+      tag: random,
+      // ?pipe=trickle(d2) delays the icon request by two seconds
+      icon: 'icon.png?pipe=trickle(d2)'
+    }).then(() => {
+      const resolveDuration = Date.now() - start;
+
+      return self.registration.getNotifications().then(notifications => {
+        event.source.postMessage({
+          type: 'notification-data',
+          resolveDuration,
+          // Check if our notification is in notifications
+          notificationReturned: notifications.some(n => n.tag == random)
+        });
+      });
+    })
+  );
+};