Implement PaymentRequestUpdateEvent

chrome/test/data/android/payments/payment_request_need_address_test.html

 <button onclick="buy()"
         id="buy"
         style="width: 50%;
                height: 50%;
                font-size: 3em;">Buy</button>
 <script>
 function print(msg) {
   document.open();
   document.write('<pre id="result" style="font-size: 3em;">' + msg + '</pre>');
   document.close();
 }
 function toDictionary(addr) {
   var dict = {};
   dict.regionCode = addr.regionCode;
   dict.administrativeArea = addr.administrativeArea;
   dict.locality = addr.locality;
   dict.dependentLocality = addr.dependentLocality;
   dict.addressLine = addr.addressLine;
   dict.postalCode = addr.postalCode;
   dict.sortingCode = addr.sortingCode;
   dict.languageCode = addr.languageCode;
   dict.organization = addr.organization;
   dict.recipient = addr.recipient;
   return dict;
 }
 function buy() {
   try {
-    var request = new PaymentRequest(['visa'], {
+    var details = {
       'items' : [ {
         'id' : 'total',
         'label' : 'Total',
         'amount' : {'currencyCode' : 'USD', 'value' : '5.00'}
-      } ],
-      'shippingOptions' : [ {
-        'id' : 'freeShippingOption',
-        'label' : 'Free global shipping',
-        'amount' : {'currencyCode' : 'USD', 'value' : '0'}
       } ]
-    },
-                                     {'requestShipping' : true});
+    };
+    var request =
+        new PaymentRequest(['visa'], details, {'requestShipping' : true});
+    request.addEventListener("shippingaddresschange", function(e) {
+      e.updateWith(new Promise(function(resolve, reject) {
+        details['shippingOptions'] = [ {
+          'id' : 'calculatedShippingOption',
+          'label' : 'Standard shipping',
+          'amount' : {'currencyCode' : 'USD', 'value' : '1.00'}
+        } ];
+        resolve(details);
+      }));
+    });
     request.show()
         .then(function(resp) {
           resp.complete(true)
               .then(function() {
                 print(request.shippingOption + '<br>' +
                       JSON.stringify(toDictionary(request.shippingAddress),
                                      undefined, 2) +
                       '<br>' + 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);
   }
 }
 </script>