[Payments] Implement openWindow for service worker based payment handler

content/common/service_worker/service_worker_messages.h

 // Copyright 2014 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.
 
 // Message definition file, included multiple times, hence no include guard.
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
@@ skipping 253 matching lines @@
 // ServiceWorker -> Browser message to request that the ServiceWorkerStorage
 // cache |data| associated with |url|.
 IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_SetCachedMetadata,
                     GURL /* url */,
                     std::vector<char> /* data */)
 
 // ServiceWorker -> Browser message to request that the ServiceWorkerStorage
 // clear the cache associated with |url|.
 IPC_MESSAGE_ROUTED1(ServiceWorkerHostMsg_ClearCachedMetadata, GURL /* url */)
 
-// Ask the browser to open a tab/window (renderer->browser).
-IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_OpenWindow,
+// Ask the browser to open a tab/window (renderer->browser) for
+// clients.openWindow.
+IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_OpenWindowForClients,
                     int /* request_id */,
                     GURL /* url */)
 
+// Ask the browser to open a tab/window (renderer->browser) for payment handler,
+// i.e., PaymentRequestEvent.openWindow().
+IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_OpenWindowForPaymentHandler,
+                    int /* request_id */,
+                    GURL /* url */)
+
 // Ask the browser to focus a client (renderer->browser).
 IPC_MESSAGE_ROUTED2(ServiceWorkerHostMsg_FocusClient,
                     int /* request_id */,
                     std::string /* uuid */)
 
 // Ask the browser to navigate a client (renderer->browser).
 IPC_MESSAGE_ROUTED3(ServiceWorkerHostMsg_NavigateClient,
                     int /* request_id */,
                     std::string /* uuid */,
                     GURL /* url */)
@@ skipping 215 matching lines @@
 
 // Sent via EmbeddedWorker as a response of NavigateClient.
 IPC_MESSAGE_CONTROL2(ServiceWorkerMsg_NavigateClientResponse,
                      int /* request_id */,
                      content::ServiceWorkerClientInfo /* client */)
 
 // Sent via EmbeddedWorker as an error response of NavigateClient.
 IPC_MESSAGE_CONTROL2(ServiceWorkerMsg_NavigateClientError,
                      int /* request_id */,
                      GURL /* url */)