PaymentHandler: Change topLevelOrigin to topOrigin (#10872)

The related spec was changed:
  https://github.com/w3c/payment-handler/pull/301

Bug: 840041
Change-Id: Ic76fffe0b974210edc3888378ded197d06e035b7
diff --git a/payment-handler/app-can-make-payment.js b/payment-handler/app-can-make-payment.js
index beec328..0bb9490 100644
--- a/payment-handler/app-can-make-payment.js
+++ b/payment-handler/app-can-make-payment.js
@@ -76,9 +76,9 @@
   }
 
   const methodAsURL = new URL(methodName);
-  if (event.topLevelOrigin !== methodAsURL.origin) {
-    const msg = `Unexpected event.topLevelOrigin: "${
-      event.topLevelOrigin
+  if (event.topOrigin !== methodAsURL.origin) {
+    const msg = `Unexpected event.topOrigin: "${
+      event.topOrigin
     }". Expected "${methodAsURL.origin}".`;
     event.respondWith(Promise.reject(new Error(msg)));
     return;
diff --git a/payment-handler/can-make-payment-event-constructor.https.worker.js b/payment-handler/can-make-payment-event-constructor.https.worker.js
index 06af7de..8ae05d7 100644
--- a/payment-handler/can-make-payment-event-constructor.https.worker.js
+++ b/payment-handler/can-make-payment-event-constructor.https.worker.js
@@ -30,13 +30,13 @@
 
 test(() => {
   const ev = new CanMakePaymentEvent('test', {
-    topLevelOrigin: 'https://foo.com',
+    topOrigin: 'https://foo.com',
     paymentRequestOrigin: 'https://bar.com',
     methodData: [],
     modifiers: [],
   });
   assert_false(ev.isTrusted, 'constructed in script, so not be trusted');
-  assert_equals(ev.topLevelOrigin, 'https://foo.com');
+  assert_equals(ev.topOrigin, 'https://foo.com');
   assert_equals(ev.paymentRequestOrigin, 'https://bar.com');
 }, 'CanMakePaymentEvent can be constructed with a CanMakePaymentEventInit, even if not trusted');