[Payments] Record CanMakePayment metrics on Desktop.

components/payments/core/test_payment_request_delegate.cc

Index: components/payments/core/test_payment_request_delegate.cc
diff --git a/components/payments/core/test_payment_request_delegate.cc b/components/payments/core/test_payment_request_delegate.cc
index f36a2a8f9b2cf80a6efe97693f7c2de36606d602..5309b1ae65581078b9c3669ee614b87ef6cee1b5 100644
--- a/components/payments/core/test_payment_request_delegate.cc
+++ b/components/payments/core/test_payment_request_delegate.cc
@@ -59,6 +59,10 @@ autofill::RegionDataLoader* TestPaymentRequestDelegate::GetRegionDataLoader() {
   return nullptr;
 }
 
+ukm::UkmService* TestPaymentRequestDelegate::GetUkmService() {
+  return nullptr;
+}
+
 TestAddressNormalizer* TestPaymentRequestDelegate::test_address_normalizer() {
   return &address_normalizer_;
 }