PaymentApp: Add interfaces for implementing InvokePaymentApp().

content/browser/payments/payment_app_provider_impl.h

Index: content/browser/payments/payment_app_provider_impl.h
diff --git a/content/browser/payments/payment_app_provider_impl.h b/content/browser/payments/payment_app_provider_impl.h
index 127e181eef875d853b89a0b38181c618485692a1..5a5a1285eb73d2e34d7a33c7ed8a2ae5a39fe414 100644
--- a/content/browser/payments/payment_app_provider_impl.h
+++ b/content/browser/payments/payment_app_provider_impl.h
@@ -25,6 +25,10 @@ class CONTENT_EXPORT PaymentAppProviderImpl : public PaymentAppProvider {
   // Should be accessed only on the UI thread.
   void GetAllManifests(BrowserContext* browser_context,
                        const GetAllManifestsCallback& callback) override;
+  void InvokePaymentApp(
+      BrowserContext* browser_context,
+      int64_t registration_id,
+      payments::mojom::PaymentAppRequestDataPtr data) override;
 
  private:
   PaymentAppProviderImpl();