[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 c0704ba17b4e4039b216dfeff3b8450e9aba9930..e123a0d4a120ac39908d7a9103a06ad8b7209d7c 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;
     }
 };
@@ -304,6 +309,12 @@ void validatePaymentDetails(const PaymentDetails& details, ExceptionState& excep
     if (details.hasModifiers()) {
         validatePaymentDetailsModifiers(details.modifiers(), exceptionState);
     }
+
+    String errorMessage;
+    if (!PaymentsValidators::isValidErrorMsgFormat(details.error(), &errorMessage)) {
+        exceptionState.throwTypeError(errorMessage);
+        return;
+    }
 }
 
 void validateAndConvertPaymentMethodData(const HeapVector<PaymentMethodData>& paymentMethodData, Vector<PaymentRequest::MethodData>* methodData, ExceptionState& exceptionState)
@@ -534,6 +545,11 @@ 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);
         m_shippingType = getValidShippingType(m_options.shippingType());