[Payments] Return the preferred payment method name to the merchant

components/payments/content/payment_request_state.h

Index: components/payments/content/payment_request_state.h
diff --git a/components/payments/content/payment_request_state.h b/components/payments/content/payment_request_state.h
index 11dc00f84151019a48596d36ec5f9d8dfc9eb3d8..6764989010c29ec3b5907a56e4230873e65ba762 100644
--- a/components/payments/content/payment_request_state.h
+++ b/components/payments/content/payment_request_state.h
@@ -22,6 +22,9 @@ namespace payments {
 
 class PaymentRequestSpec;
 
+// Identifier for the BasicCard payment method.
+extern const char kBasicCardMethodName[];
+
 // Keeps track of the information currently selected by the user and whether the
 // user is ready to pay. Uses information from the PaymentRequestSpec, which is
 // what the merchant has specified, as input into the "is ready to pay"