[Payments] Use formatter currency code on desktop

components/payments/payment_request.mojom

Index: components/payments/payment_request.mojom
diff --git a/components/payments/payment_request.mojom b/components/payments/payment_request.mojom
index 82e005f7e8c4d13455b8ae5456b4a679c2059b76..5b1abcdea2394f5e7e1cb56ee269dea2a18e972f 100644
--- a/components/payments/payment_request.mojom
+++ b/components/payments/payment_request.mojom
@@ -44,11 +44,11 @@ struct PaymentCurrencyAmount {
   // digits. Separated by a dot.
   string value;
 
-  // currencySystem is a URL that indicates the currency system that the
+  // currency_system is a URL that indicates the currency system that the
   // currency identifier belongs to. By default, the value is
   // urn:iso:std:iso:4217 indicating that currency is defined by [ISO4217]
   // (for example, USD for US Dollars).
-  string? currencySystem;
+  string? currency_system;
 };
 
 struct PaymentResponse {
@@ -212,7 +212,7 @@ enum PaymentComplete {
 
 interface PaymentRequest {
   Init(PaymentRequestClient client,
-       array<PaymentMethodData> methodData,
+       array<PaymentMethodData> method_data,
        PaymentDetails details,
        PaymentOptions options);
   Show();