[Web Payments] Add Spinners and timeout while waiting for UpdateWith

components/payments/content/payment_request_spec.cc

Index: components/payments/content/payment_request_spec.cc
diff --git a/components/payments/content/payment_request_spec.cc b/components/payments/content/payment_request_spec.cc
index bec17e27c30289c3bf12b8a92d23a2122d1c1e19..891caa2767a82b880dbac7d412810ae35166515d 100644
--- a/components/payments/content/payment_request_spec.cc
+++ b/components/payments/content/payment_request_spec.cc
@@ -127,6 +127,12 @@ std::string PaymentRequestSpec::GetFormattedCurrencyCode() {
   return formatter->formatted_currency_code();
 }
 
+void PaymentRequestSpec::StartWaitingForUpdateWith(
+    PaymentRequestSpec::UpdateReason reason) {
+  for (auto& observer : observers_)
+    observer.OnStartUpdating(reason);
+}
+
 void PaymentRequestSpec::PopulateValidatedMethodData(
     const std::vector<mojom::PaymentMethodDataPtr>& method_data_mojom) {
   if (method_data_mojom.empty()) {