[Web Payments] Implement the credit card selection UI functionality.

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 e3de7b511cdebfc547166d63d7af431e58886fd3..df302b0f1c5b41aa47bb614f3ca36582ea87943a 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 +29,10 @@ enum class DialogViewID : int {
   ORDER_SUMMARY_LINE_ITEM_2,
   ORDER_SUMMARY_LINE_ITEM_3,
 
+  // The following are views contained within the Payment Method Sheet.
+  PAYMENT_METHOD_SHEET_LIST_VIEW,
+  PAYMENT_METHOD_ITEM_CHECKMARK_VIEW,
+
   // Used to label the error labels with an offset, which gets added to
   // the Autofill type value they represent (for tests).
   ERROR_LABEL_OFFSET,