Duplicate payment method identifiers in methodData and details.modififiers should throw TypeError.

third_party/WebKit/Source/modules/payments/PaymentRequest.cpp

Index: third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
index e3da8a51339833091acfc3cae2bc2ca25a1ecf31..2c5983de3ba29908cd09bc38f19e2d1a2ad32fa9 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
@@ -224,10 +224,19 @@ void validatePaymentDetailsModifiers(const HeapVector<PaymentDetailsModifier>& m
         return;
     }
 
+    HashSet<String> uniqueMethods;
     for (const auto& modifier : modifiers) {
         if (modifier.supportedMethods().isEmpty()) {
             exceptionState.throwTypeError("Must specify at least one payment method identifier");
             return;
+        } else {

[please use gerrit instead, 2016/07/06 07:31:56]

No need for "else", because the previous clause returns.

[pals, 2016/07/07 05:14:13]

Done.

+            for (const auto& method : modifier.supportedMethods()) {
+                if (uniqueMethods.contains(method)) {
+                    exceptionState.throwTypeError("Duplicate payment method identifiers are not allowed");
+                    return;
+                }
+                uniqueMethods.add(method);
+            }
         }
 
         if (modifier.hasTotal()) {
@@ -289,10 +298,19 @@ void validateAndConvertPaymentMethodData(const HeapVector<PaymentMethodData>& pa
         return;
     }
 
+    HashSet<String> uniqueMethods;
     for (const auto& pmd : paymentMethodData) {
         if (pmd.supportedMethods().isEmpty()) {
             exceptionState.throwTypeError("Must specify at least one payment method identifier");
             return;
+        } else {

[please use gerrit instead, 2016/07/06 07:31:56]

Ditto.

[pals, 2016/07/07 05:14:13]

Done.

+            for (const auto& method : pmd.supportedMethods()) {
+                if (uniqueMethods.contains(method)) {
+                    exceptionState.throwTypeError("Duplicate payment method identifiers are not allowed");
+                    return;
+                }
+                uniqueMethods.add(method);
+            }
         }
 
         String stringifiedData = "";