[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..ff678986c1c434db7b00911917e9f7e6ccc0cb75 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::String("");

[haraken, 2016/09/20 14:46:53]

WTF::emptyString() ?

[Hwanseung Lee, 2016/09/20 15:08:44]

it is my intention. thank you.

+
         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("must be Error value  empty");

[please use gerrit instead, 2016/09/20 15:40:50]

"Error value should be empty"

[Hwanseung Lee, 2016/09/20 16:01:09]

Done.

+        return;
+    }
+
     if (m_options.requestShipping())
         m_shippingOption = getSelectedShippingOption(details);