PaymentApp: Implement respondWith() in PaymentRequestEvent. (content side)

content/public/browser/payment_app_provider.h

Index: content/public/browser/payment_app_provider.h
diff --git a/content/public/browser/payment_app_provider.h b/content/public/browser/payment_app_provider.h
index 5a70e02f3125106b3247804e53aac9288fc9e276..973f1423cd88a7dd56a3888ad8d68db670d4f6d7 100644
--- a/content/public/browser/payment_app_provider.h
+++ b/content/public/browser/payment_app_provider.h
@@ -31,6 +31,8 @@ class CONTENT_EXPORT PaymentAppProvider {
       std::pair<int64_t, payments::mojom::PaymentAppManifestPtr>;
   using Manifests = std::vector<ManifestWithID>;
   using GetAllManifestsCallback = base::Callback<void(Manifests)>;
+  using InvokePaymentAppCallback =
+      base::Callback<void(payments::mojom::PaymentAppResponsePtr)>;
 
   // Should be accessed only on the UI thread.
   virtual void GetAllManifests(BrowserContext* browser_context,
@@ -38,7 +40,8 @@ class CONTENT_EXPORT PaymentAppProvider {
   virtual void InvokePaymentApp(
       BrowserContext* browser_context,
       int64_t registration_id,
-      payments::mojom::PaymentAppRequestPtr app_request) = 0;
+      payments::mojom::PaymentAppRequestPtr app_request,
+      const InvokePaymentAppCallback& callback) = 0;
 
  protected:
   virtual ~PaymentAppProvider() {}