enable modifiers for native apps

chrome/test/data/payments/bobpay_and_basic_card_with_modifiers.js

+/*
+ * Copyright 2017 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* global PaymentRequest:false */
+
+/**
+ * Launches the PaymentRequest UI with Bob Pay and basic-card as payment
+ * methods.
+ */
+function buy() {  // eslint-disable-line no-unused-vars
+  try {
+    new PaymentRequest(
+        [{supportedMethods: ['https://bobpay.com', 'basic-card']}],
+        {
+          total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
+          modifiers: [{
+            supportedMethods: ['https://bobpay.com'],
+            total: {
+              label: 'Total',
+              amount: {currency: 'USD', value: '4.00'}
+            },
+            additionalDisplayItems: [{
+              label: 'BobPay discount',
+              amount: {currency: 'USD', value: '-1.00'}
+            }],
+            data: {discountProgramParticipantId: '86328764873265'}
+          }],
+        })
+        .show()
+        .then(function(resp) {
+          resp.complete('success')
+              .then(function() {
+                print(
+                    resp.methodName + '<br>' +
+                    JSON.stringify(resp.details, undefined, 2));
+              })
+              .catch(function(error) {
+                print(error.message);
+              });
+        })
+        .catch(function(error) {
+          print(error.message);
+        });
+  } catch (error) {
+    print(error.message);
+  }
+}