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

components/payments/content/payment_app.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module payments.mojom;
 
 import "components/payments/content/payment_request.mojom";
+import "mojo/common/time.mojom";
 import "url/mojo/url.mojom";
 
 enum PaymentAppManifestError {
   NONE,
   NOT_IMPLEMENTED,
   NO_ACTIVE_WORKER,
   MANIFEST_STORAGE_OPERATION_FAILED,
 };
 
 struct PaymentAppOption {
@@ skipping 17 matching lines @@
       => (PaymentAppManifest payment_app_manifest, PaymentAppManifestError error);
 };
 
 struct PaymentAppRequest {
   url.mojom.Url origin;
   array<PaymentMethodData> methodData;
   PaymentItem total;
   array<PaymentDetailsModifier> modifiers;
   string optionId;
 };
+
+struct PaymentAppResponse {

[please use gerrit instead, 2017/03/21 16:09:40]

If mojom language supports inheritance, then please move PaymentAppResponse to
payment_request.mojom, then make PaymentResponse inherit from
PayemntAppResponse.

[zino, 2017/03/22 18:04:44]

As far as I know, the mojom struct doesn't support inheritance :(

I try to find codes in cs.chromium.org but I didn't find anything:
|struct\ [A-Z|a-z|1-9|_]*\ [^\{]  file:.*mojom$ package:^chromium$|

Also, I found the following link:
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-mojo/6_Kw33AiH0A

+  string method_name;
+  string stringified_details;
+};
+
+interface PaymentAppResponseCallback {

[please use gerrit instead, 2017/03/21 16:09:40]

Nit: would be more clear to have an interface like this, don't you think?

interface PaymentApp {
  InvokePaymentApp(PaymentAppRequest request)
      => (PaymentAppResponse response,
          mojo.common.mojom.Time dispatch_even_type);
};

[zino, 2017/03/22 18:04:44]

To dispatch PaymentRequestEvent in registered service worker, we use the
DispatchPaymentRequestEvent() function in service_worker_event_dispatcher.mojom.
This interface is to provide a callback for respondWith() in blink side.
I left comments.

+  OnPaymentAppResponse(payments.mojom.PaymentAppResponse response,

[please use gerrit instead, 2017/03/21 16:09:40]

No need for "payments.mojom." module name here, because that's the module of
this file.

[zino, 2017/03/22 18:04:44]

Done.

+                       mojo.common.mojom.Time dispatch_event_time);
+};