[Payment Request] Generic edit form

ios/showcase/core/showcase_model.mm

Index: ios/showcase/core/showcase_model.mm
diff --git a/ios/showcase/core/showcase_model.mm b/ios/showcase/core/showcase_model.mm
index 9e2edd93640d3ede15cc3ec97438b6c656c7d73b..99fc26262daae5b23237746741e5d617f9ea4c9a 100644
--- a/ios/showcase/core/showcase_model.mm
+++ b/ios/showcase/core/showcase_model.mm
@@ -51,6 +51,11 @@
       showcase::kClassForInstantiationKey : @"SCToolbarCoordinator",
       showcase::kUseCaseKey : @"Toolbar",
     },
+    @{
+      showcase::kClassForDisplayKey : @"PaymentRequestEditViewController",
+      showcase::kClassForInstantiationKey : @"SCPaymentsEditorCoordinator",
+      showcase::kUseCaseKey : @"Generic payment request editor",
+    },
   ];
 }