Duplicate shipping option identifiers should throw TypeError.

third_party/WebKit/LayoutTests/payments/payment-request-interface.html

Index: third_party/WebKit/LayoutTests/payments/payment-request-interface.html
diff --git a/third_party/WebKit/LayoutTests/payments/payment-request-interface.html b/third_party/WebKit/LayoutTests/payments/payment-request-interface.html
index c0854654bec17714e7211eaed86cbd6ef52c9da9..670f291bc40cd0322cd2fb8281e56c03f1d4e48f 100644
--- a/third_party/WebKit/LayoutTests/payments/payment-request-interface.html
+++ b/third_party/WebKit/LayoutTests/payments/payment-request-interface.html
@@ -204,6 +204,10 @@ generate_tests(assert_throws, [
     ['Duplicate supported payment method identifiers should throw TypeError.', null, function() {
         new PaymentRequest([{'supportedMethods': ['foo']}, {'supportedMethods': ['foo']}], buildDetails(), {})
     }],
+    ['Duplicate shipping option identifiers should throw TypeError.', null, function() {
+        var shippingOptions = [buildItem({'id': 'express', 'selected': false}), buildItem({'id': 'express', 'selected': true})];
+        new PaymentRequest([{'supportedMethods': ['foo']}], {'total': buildItem(), 'displayItems': [buildItem()], 'shippingOptions': shippingOptions}, {'requestShipping': true})
+    }],
     ['Absence of total should throw TypeError.', null, function() {
         new PaymentRequest([{'supportedMethods': ['foo']}], {'displayItems': [buildItem()]})
     }],