Add pending line item support for web payments.

chrome/test/data/android/payments/dynamic_shipping.js

 /*
  * Copyright 2016 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 */
 /* global toDictionary:false */
 
 /**
  * Launches the PaymentRequest UI that offers free shipping in California and
  * $5.00 shipping in US. Does not allow shipping outside of US.
  */
 function buy() {  // eslint-disable-line no-unused-vars
   try {
     var details = {
       total: {label: 'Total', amount: {currency: 'USD', value: '5.00'}},
-      displayItems:
-          [{label: 'Subtotal', amount: {currency: 'USD', value: '5.00'}}]
+      displayItems: [
+        {
+          label: 'Pending shipping price',
+          amount: {currency: 'USD', value: '0.00'},
+          pending: true
+        },
+        {
+          label: 'Subtotal',
+          amount: {currency: 'USD', value: '5.00'}
+        }
+      ]
     };
 
     var request = new PaymentRequest(
         [{supportedMethods: ['visa']}], details, {requestShipping: true});
 
     request.addEventListener('shippingaddresschange', function(evt) {
       evt.updateWith(new Promise(function(resolve) {
         resolve(updateDetails(details, request.shippingAddress));
       }));
     });
@@ skipping 39 matching lines @@
     if (addr.region === 'CA') {
       shippingOption.id = 'californiaShippingOption';
       shippingOption.label = 'Free shipping in California';
       details.total.amount.value = '5.00';
     } else {
       shippingOption.id = 'usShippingOption';
       shippingOption.label = 'Standard shipping in US';
       shippingOption.amount.value = '5.00';
       details.total.amount.value = '10.00';
     }
-    if (details.displayItems.length === 1) {
-      details.displayItems.splice(0, 0, shippingOption);
-    } else {
-      details.displayItems.splice(0, 1, shippingOption);
-    }
+    details.displayItems.splice(0, 1, shippingOption);
     details.shippingOptions = [shippingOption];
   } else {
     delete details.shippingOptions;
   }
   return details;
 }