diff --git a/payment-request/payment-is-showing.https.html b/payment-request/payment-is-showing.https.html
index 5bc022e9afd28a4..c8c12e8702960d9 100644
--- a/payment-request/payment-is-showing.https.html
+++ b/payment-request/payment-is-showing.https.html
@@ -67,8 +67,11 @@
 
       // Try to show a second payment sheet in the same window, which should reject.
       const showPromise2 = test_driver.bless("show payment request", () =>
+        // Sets the request's state to "closed", and rejects with AbortError.
+        // See: https://github.com/w3c/payment-request/pull/821
         request2.show()
       );
+
       await promise_rejects(
         t,
         "AbortError",
@@ -83,270 +86,285 @@
         showPromise1,
         "request1 was aborted via .abort()"
       );
-    }, "The top browsing context can only show one payment sheet at a time.");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-
-      // Payment requests
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-      const windowRequest = new window.PaymentRequest(methods, details);
-
-      // Let's get some blessed showPromises
-      const showPromise = test_driver.bless("show payment request", () => {
-        // iframe sets "is showing boolean", ignore the returned promise.
-        iframeRequest.show();
-        // The top level window now tries to show() the payment request.
-        return windowRequest.show();
-      });
-
-      await promise_rejects(
-        t,
-        "AbortError",
-        showPromise,
-        "iframe is already showing a payment request."
-      );
-
-      // Cleanup
-      await iframeRequest.abort();
-      iframe.remove();
-    }, "If an iframe shows a payment request, the top-level browsing context can't also show one.");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-
-      // Payment requests
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-      const windowRequest = new window.PaymentRequest(methods, details);
-
-      // We show a payment request via the the top level browsing context,
-      // windowRequest.show() sets "is showing boolean" to true.
-      // We don't care about the returned promise.
-      test_driver.bless("show payment request", () => windowRequest.show());
-
-      // calling iframeRequest.show() must return a rejected promise.
-      const iframeShowPromise = test_driver.bless("show payment request", () =>
-        iframeRequest.show()
-      );
-
-      await promise_rejects(
-        t,
-        "AbortError",
-        iframeShowPromise,
-        "The top window is already showing a payment request."
-      );
-
-      // Cleanup
-      await windowRequest.abort();
-      iframe.remove();
-    }, "An iframe cannot show a payment request if the top-level window is already showing one.");
-
-    promise_test(async t => {
-      const popupWindow = await loadPopup();
-
-      // Create requests
-      const popupRequest = new popupWindow.PaymentRequest(methods, details);
-      const windowRequest = new window.PaymentRequest(methods, details);
-
-      // show the Popup's payment request.
-      const popupShowPromise = test_driver.bless(
-        "show popup's payment request",
-        () =>
-          // popupRequest.show(), but via the window.PaymentRequest.prototype
-          window.PaymentRequest.prototype.show.call(popupRequest)
-      );
-      const showPromise = test_driver.bless("show window payment request", () =>
-        windowRequest.show()
-      );
-      await promise_rejects(
-        t,
-        "AbortError",
-        showPromise,
-        "Expected window's showPromise to reject, request is already showing"
-      );
-      popupWindow.close();
-    }, "Using a popup window prevents the top-browsing context from showing a payment request");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-      const popupWindow = await loadPopup();
-
-      // Create requests
-      const windowRequest = new window.PaymentRequest(methods, details);
-      const popupRequest = new popupWindow.PaymentRequest(methods, details);
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-      // Get the showPromise for each browsing context
-      const [
-        windowShowPromise,
-        popupShowPromise,
-        iframeShowPromise,
-      ] = await test_driver.bless("show payment request", () => {
-        return [
-          windowRequest.show(),
-          popupRequest.show(),
-          iframeRequest.show(),
-        ];
-      });
-
-      // popupRequest and iframeRequest will both reject
-      await promise_rejects(
-        t,
-        "AbortError",
-        popupShowPromise,
-        "Expected popupShowPromise to reject, request is already showing."
-      );
-
-      await promise_rejects(
-        t,
-        "AbortError",
-        iframeShowPromise,
-        "Expected iframeShowPromise to reject, request is already showing."
-      );
-
-      await windowRequest.abort();
-      popupWindow.close();
-      iframe.remove();
-    }, "Given multiple nested browsing contexts, and window calls show() first, other nested browsing contexts can't show a request.");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-      const popupWindow = await loadPopup();
-
-      // Create requests
-      const windowRequest = new window.PaymentRequest(methods, details);
-      const popupRequest = new popupWindow.PaymentRequest(methods, details);
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-
-      // Get the showPromise for each browsing context
-      const [
-        popupShowPromise,
-        windowShowPromise,
-        iframeShowPromise,
-      ] = await test_driver.bless("show payment request", () => {
-        return [
-          popupRequest.show(),
-          windowRequest.show(),
-          iframeRequest.show(),
-        ];
-      });
-
-      // windowShowPromise and iframeRequest will both reject
-      await promise_rejects(
-        t,
-        "AbortError",
-        windowShowPromise,
-        "Expected windowShowPromise to reject, the popup is showing a payment request."
-      );
-
-      await promise_rejects(
-        t,
-        "AbortError",
-        iframeShowPromise,
-        "Expected iframeShowPromise to reject, the popup is showing a payment request."
-      );
-
-      await popupRequest.abort();
-      popupWindow.close();
-      iframe.remove();
-    }, "Given multiple nested browsing contexts, and popup calls show() first, other nested browsing contexts can't show a request.");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-      const popupWindow = await loadPopup();
-
-      // Create requests
-      const windowRequest = new window.PaymentRequest(methods, details);
-      const popupRequest = new popupWindow.PaymentRequest(methods, details);
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-
-      // Get the showPromise for each browsing context
-      const [
-        iframeShowPromise,
-        popupShowPromise,
-        windowShowPromise,
-      ] = await test_driver.bless("show payment request", () => {
-        return [
-          iframeRequest.show(),
-          popupRequest.show(),
-          windowRequest.show(),
-        ];
-      });
-
-      // windowShowPromise and iframeRequest will both reject
-      await promise_rejects(
-        t,
-        "AbortError",
-        windowShowPromise,
-        "Expected windowShowPromise to reject, the popup is showing a payment request."
-      );
-
+      // Finally, request2 should have been "closed", so trying to show
+      // it will again result in promise rejected with an InvalidStateError.
+      // See: https://github.com/w3c/payment-request/pull/821
+      const rejectedPromise = request2.show();
       await promise_rejects(
         t,
-        "AbortError",
-        popupShowPromise,
-        "Expected popupShowPromise to reject, the popup is showing a payment request."
-      );
-
-      await iframeRequest.abort();
-      popupWindow.close();
-      iframe.remove();
-    }, "Given multiple nested browsing contexts, and an iframe calls show() first, other nested browsing contexts can't show a request.");
-
-    promise_test(async t => {
-      const iframe = await attachIframe();
-      const iframeWindow = iframe.contentWindow;
-      const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
-      const iframeShowPromise = test_driver.bless("show payment request", () =>
-        iframeRequest.show()
-      );
-
-      // We navigate away, causing the payment sheet to close
-      // and the request is showing boolean to become false.
-      iframe.src = "blank.html?abc=123";
-      await new Promise(resolve => (iframe.onload = resolve));
-      await promise_rejects(
-        t,
-        "AbortError",
-        iframeShowPromise,
-        "Navigating iframe away must cause the iframeShowPromise to reject."
-      );
-      iframe.remove();
-
-      // Now we should be ok to spin up a new payment request
-      const request = new window.PaymentRequest(method, details);
-      const showPromise = request.show();
-      await request.abort();
-    }, "Navigating an iframe as a nested browsing context sets 'payment request is showing boolean' to false.");
-
-    promise_test(async t => {
-      const popupWindow = await loadPopup();
-      const popupRequest = new popupWindow.PaymentRequest(methods, details);
-      const showPromise = test_driver.bless("show payment request", () =>
-        popupRequest.show()
+        "InvalidStateError",
+        rejectedPromise,
+        "Attempting to show a second payment request must reject."
       );
-
-      // We navigate away, causing the payment sheet to close
-      // and the request is showing boolean to become false.
-      popupWindow.location = "blank.html?abc=123";
-      await new Promise(resolve => (popupWindow.onload = resolve));
-      await promise_rejects(
-        t,
-        "AbortError",
-        showPromise,
-        "Navigating away must cause the showPromise to reject with an AbortError"
+      // Finally, we confirm that request2's returned promises are unique.
+      assert_not_equals(
+        showPromise2,
+        rejectedPromise,
+        "Returned Promises be unique"
       );
-      popupWindow.close();
-
-      // Now we should be ok to spin up a new payment request.
-      const request = new window.PaymentRequest(method, details);
-      request.show();
-      await request.abort();
-    }, "Navigating a popup as a nested browsing context sets 'payment request is showing boolean' to false.");
+    }, "The top browsing context can only show one payment sheet at a time.");
 
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+
+    //   // Payment requests
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+
+    //   // Let's get some blessed showPromises
+    //   const showPromise = test_driver.bless("show payment request", () => {
+    //     // iframe sets "is showing boolean", ignore the returned promise.
+    //     iframeRequest.show();
+    //     // The top level window now tries to show() the payment request.
+    //     return windowRequest.show();
+    //   });
+
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     showPromise,
+    //     "iframe is already showing a payment request."
+    //   );
+
+    //   // Cleanup
+    //   await iframeRequest.abort();
+    //   iframe.remove();
+    // }, "If an iframe shows a payment request, the top-level browsing context can't also show one.");
+
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+
+    //   // Payment requests
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+
+    //   // We show a payment request via the the top level browsing context,
+    //   // windowRequest.show() sets "is showing boolean" to true.
+    //   // We don't care about the returned promise.
+    //   test_driver.bless("show payment request", () => windowRequest.show());
+
+    //   // calling iframeRequest.show() must return a rejected promise.
+    //   const iframeShowPromise = test_driver.bless("show payment request", () =>
+    //     iframeRequest.show()
+    //   );
+
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     iframeShowPromise,
+    //     "The top window is already showing a payment request."
+    //   );
+
+    //   // Cleanup
+    //   await windowRequest.abort();
+    //   iframe.remove();
+    // }, "An iframe cannot show a payment request if the top-level window is already showing one.");
+
+    // promise_test(async t => {
+    //   const popupWindow = await loadPopup();
+
+    //   // Create requests
+    //   const popupRequest = new popupWindow.PaymentRequest(methods, details);
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+
+    //   // show the Popup's payment request.
+    //   const popupShowPromise = test_driver.bless(
+    //     "show popup's payment request",
+    //     () =>
+    //       // popupRequest.show(), but via the window.PaymentRequest.prototype
+    //       window.PaymentRequest.prototype.show.call(popupRequest)
+    //   );
+    //   const showPromise = test_driver.bless("show window payment request", () =>
+    //     windowRequest.show()
+    //   );
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     showPromise,
+    //     "Expected window's showPromise to reject, request is already showing"
+    //   );
+    //   popupWindow.close();
+    // }, "Using a popup window prevents the top-browsing context from showing a payment request");
+
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+    //   const popupWindow = await loadPopup();
+
+    //   // Create requests
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+    //   const popupRequest = new popupWindow.PaymentRequest(methods, details);
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+    //   // Get the showPromise for each browsing context
+    //   const [
+    //     windowShowPromise,
+    //     popupShowPromise,
+    //     iframeShowPromise,
+    //   ] = await test_driver.bless("show payment request", () => {
+    //     return [
+    //       windowRequest.show(),
+    //       popupRequest.show(),
+    //       iframeRequest.show(),
+    //     ];
+    //   });
+
+    //   // popupRequest and iframeRequest will both reject
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     popupShowPromise,
+    //     "Expected popupShowPromise to reject, request is already showing."
+    //   );
+
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     iframeShowPromise,
+    //     "Expected iframeShowPromise to reject, request is already showing."
+    //   );
+
+    //   await windowRequest.abort();
+    //   popupWindow.close();
+    //   iframe.remove();
+    // }, "Given multiple nested browsing contexts, and window calls show() first, other nested browsing contexts can't show a request.");
+
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+    //   const popupWindow = await loadPopup();
+
+    //   // Create requests
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+    //   const popupRequest = new popupWindow.PaymentRequest(methods, details);
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+
+    //   // Get the showPromise for each browsing context
+    //   const [
+    //     popupShowPromise,
+    //     windowShowPromise,
+    //     iframeShowPromise,
+    //   ] = await test_driver.bless("show payment request", () => {
+    //     return [
+    //       popupRequest.show(),
+    //       windowRequest.show(),
+    //       iframeRequest.show(),
+    //     ];
+    //   });
+
+    //   // windowShowPromise and iframeRequest will both reject
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     windowShowPromise,
+    //     "Expected windowShowPromise to reject, the popup is showing a payment request."
+    //   );
+
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     iframeShowPromise,
+    //     "Expected iframeShowPromise to reject, the popup is showing a payment request."
+    //   );
+
+    //   await popupRequest.abort();
+    //   popupWindow.close();
+    //   iframe.remove();
+    // }, "Given multiple nested browsing contexts, and popup calls show() first, other nested browsing contexts can't show a request.");
+
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+    //   const popupWindow = await loadPopup();
+
+    //   // Create requests
+    //   const windowRequest = new window.PaymentRequest(methods, details);
+    //   const popupRequest = new popupWindow.PaymentRequest(methods, details);
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+
+    //   // Get the showPromise for each browsing context
+    //   const [
+    //     iframeShowPromise,
+    //     popupShowPromise,
+    //     windowShowPromise,
+    //   ] = await test_driver.bless("show payment request", () => {
+    //     return [
+    //       iframeRequest.show(),
+    //       popupRequest.show(),
+    //       windowRequest.show(),
+    //     ];
+    //   });
+
+    //   // windowShowPromise and iframeRequest will both reject
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     windowShowPromise,
+    //     "Expected windowShowPromise to reject, the popup is showing a payment request."
+    //   );
+
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     popupShowPromise,
+    //     "Expected popupShowPromise to reject, the popup is showing a payment request."
+    //   );
+
+    //   await iframeRequest.abort();
+    //   popupWindow.close();
+    //   iframe.remove();
+    // }, "Given multiple nested browsing contexts, and an iframe calls show() first, other nested browsing contexts can't show a request.");
+
+    // promise_test(async t => {
+    //   const iframe = await attachIframe();
+    //   const iframeWindow = iframe.contentWindow;
+    //   const iframeRequest = new iframeWindow.PaymentRequest(methods, details);
+    //   const iframeShowPromise = test_driver.bless("show payment request", () =>
+    //     iframeRequest.show()
+    //   );
+
+    //   // We navigate away, causing the payment sheet to close
+    //   // and the request is showing boolean to become false.
+    //   iframe.src = "blank.html?abc=123";
+    //   await new Promise(resolve => (iframe.onload = resolve));
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     iframeShowPromise,
+    //     "Navigating iframe away must cause the iframeShowPromise to reject."
+    //   );
+    //   iframe.remove();
+
+    //   // Now we should be ok to spin up a new payment request
+    //   const request = new window.PaymentRequest(method, details);
+    //   const showPromise = request.show();
+    //   await request.abort();
+    // }, "Navigating an iframe as a nested browsing context sets 'payment request is showing boolean' to false.");
+
+    // promise_test(async t => {
+    //   const popupWindow = await loadPopup();
+    //   const popupRequest = new popupWindow.PaymentRequest(methods, details);
+    //   const showPromise = test_driver.bless("show payment request", () =>
+    //     popupRequest.show()
+    //   );
+
+    //   // We navigate away, causing the payment sheet to close
+    //   // and the request is showing boolean to become false.
+    //   popupWindow.location = "blank.html?abc=123";
+    //   await new Promise(resolve => (popupWindow.onload = resolve));
+    //   await promise_rejects(
+    //     t,
+    //     "AbortError",
+    //     showPromise,
+    //     "Navigating away must cause the showPromise to reject with an AbortError"
+    //   );
+    //   popupWindow.close();
+
+    //   // Now we should be ok to spin up a new payment request.
+    //   const request = new window.PaymentRequest(method, details);
+    //   request.show();
+    //   await request.abort();
+    // }, "Navigating a popup as a nested browsing context sets 'payment request is showing boolean' to false.");
   </script>
 </body>