[PaymentReqeust] Add error message in PaymentDetails. (in blink side)

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 0adcb7c08c18fef7a5854aad5bb668a64e8c21d6..fe84aca14add17eb173ed63ab0653d55be4b7ac0 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
@@ -125,6 +125,11 @@ struct TypeConverter<PaymentDetailsPtr, blink::PaymentDetails> {
         else
             output->modifiers = mojo::WTFArray<PaymentDetailsModifierPtr>::New(0);
 
+        if (input.hasError())
+            output->error = input.error();
+        else
+            output->error = WTF::emptyString();
+
         return output;
     }
 };
@@ -519,6 +524,11 @@ PaymentRequest::PaymentRequest(ScriptState* scriptState, const HeapVector<Paymen
     if (exceptionState.hadException())
         return;
 
+    if (details.hasError() && !details.error().isEmpty()) {
+        exceptionState.throwTypeError("Error value should be empty");
+        return;
+    }
+
     if (m_options.requestShipping())
         m_shippingOption = getSelectedShippingOption(details);