PaymentHandler: Implement PaymentInstruments.has().

third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html

Index: third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html b/third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html
index 7f6c7fbf89d00e5cf05cd1e69c2f9616d6b2b6d4..8f36fcaf5e9f7e494e4f6a16157e7c86a40ccd60 100644
--- a/third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html
+++ b/third_party/WebKit/LayoutTests/http/tests/payments/payment-instruments.html
@@ -82,4 +82,41 @@ promise_test(test => {
       .catch(unreached_rejection(test));
   }, 'PaymentInstruments delete method test');
 
+promise_test(test => {
+    var registration;
+    var script_url = 'resources/empty-worker.js';
+    var scope = 'resources/';
+
+    return service_worker_unregister_and_register(test, script_url, scope)
+      .then(r => {
+          registration = r;
+          return wait_for_state(test, registration.installing, 'activated');
+        })
+      .then(state => {
+          assert_equals(state, 'activated');
+          return registration.paymentManager.instruments.set(
+              'test_key',
+              {
+                name: 'Visa ending ****4756',
+                enabledMethods: ['basic-card'],
+                capabilities: {
+                  supportedNetworks: ['visa'],
+                  supportedTypes: ['credit']
+                }
+              });
+        })
+      .then(result => {
+          assert_equals(result, undefined);
+          return registration.paymentManager.instruments.has('test_key');
+        })
+      .then(result => {
+          assert_equals(result, true);
+          return registration.paymentManager.instruments.has('unstored_test_key');
+        })
+      .then(result => {
+          assert_equals(result, false);
+        })
+      .catch(unreached_rejection(test));
+  }, 'PaymentInstruments |has| method test');
+
 </script>