Add billing address as a mandatory field of Payments credit cards.

chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h

Index: chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h
diff --git a/chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h b/chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h
index cce2f807abb80afcca758999b6e2c04f90592443..2899ca6c4fed5d217eeabefd3d04bd28a8a60b6b 100644
--- a/chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h
+++ b/chrome/browser/ui/views/payments/payment_request_dialog_view_ids.h
@@ -29,6 +29,8 @@ enum class DialogViewID : int {
   CANCEL_BUTTON,
   BACK_BUTTON,
   CVC_PROMPT_CONFIRM_BUTTON,
+  ADD_BILLING_ADDRESS_BUTTON,
+  SAVE_ADDRESS_BUTTON,
 
   // The following are buttons that are displayed inline in the Payment Sheet
   // sections when no option is selected or available.
@@ -66,6 +68,9 @@ enum class DialogViewID : int {
 
   // The CVC text field in the unmask sheet.
   CVC_PROMPT_TEXT_FIELD,
+
+  // The combobox to choose a billing address to associate to a credit card.
+  CREDIT_CARD_BILLING_ADDRESS,
 };
 
 }  // namespace payments