Properly queue messages sent to message ports that are transferred to a service worker.

content/browser/message_port_service.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_BROWSER_MESSAGE_PORT_SERVICE_H_
 #define CONTENT_BROWSER_MESSAGE_PORT_SERVICE_H_
 
 #include <map>
 #include <utility>
 #include <vector>
@@ skipping 19 matching lines @@
               MessagePortMessageFilter* filter,
               int* message_port_id);
   void Destroy(int message_port_id);
   void Entangle(int local_message_port_id, int remote_message_port_id);
   void PostMessage(int sender_message_port_id,
                    const base::string16& message,
                    const std::vector<int>& sent_message_port_ids);
   void QueueMessages(int message_port_id);
   void SendQueuedMessages(int message_port_id,
                           const QueuedMessages& queued_messages);
+  void ReleaseMessages(int message_port_id);
 
   // Updates the information needed to reach a message port when it's sent to a
   // (possibly different) process.
   void UpdateMessagePort(
       int message_port_id,
       MessagePortMessageFilter* filter,
       int routing_id);
 
+  // The message port is being transferred to a new renderer process, but the
+  // code doing that isn't able to immediately update the message port with a
+  // new filter and routing_id. This queues up all messages sent to this port
+  // until later ReleaseMessages is called for this port (this will happen
+  // automatically as soon as a WebMessagePortChannelImpl instance is created
+  // for this port in the renderer. The browser side code is still responsible
+  // for updating the port with a new filter before that happens. If ultimately
+  // transfering the port to a new process fails, ClosePort should be called to
+  // clean up the port.
+  void HoldMessages(int message_port_id);
+
+  // Closes and cleans up the message port.
+  void ClosePort(int message_port_id);
+
   void OnMessagePortMessageFilterClosing(MessagePortMessageFilter* filter);
 
   // Attempts to send the queued messages for a message port.
   void SendQueuedMessagesIfPossible(int message_port_id);
 
  private:
   friend struct DefaultSingletonTraits<MessagePortService>;
 
   MessagePortService();
   ~MessagePortService();
@@ skipping 12 matching lines @@
 
   // We need globally unique identifiers for each message port.
   int next_message_port_id_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePortService);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MESSAGE_PORT_SERVICE_H_