Hold messages in message port service when a message port is

content/public/browser/message_port_provider.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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_MESSAGE_PORT_PROVIDER_H_
 #define CONTENT_PUBLIC_BROWSER_MESSAGE_PORT_PROVIDER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 36 matching lines @@
 
   // Posts a MessageEvent to a message port associated with a message channel.
   static void PostMessageToPort(
       int sender_port_id,
       const MessagePortMessage& message,
       const std::vector<TransferredMessagePort>& sent_ports);
 
   // Close the message port. Should be called on IO thread.
   static void ClosePort(int message_port_id);
 
+  // Queue up all the messages for this message port until ReleaseMessages
+  // is called. Should be called on IO thread.
+  static void HoldMessages(int message_port_id);
+
+  // Release any queued messages as a result of HoldMessages. Should be
+  // called on IO thread.
+  static void ReleaseMessages(int message_port_id);
+
   // Cleanup the message ports that belong to the closing delegate.
   static void OnMessagePortDelegateClosing(MessagePortDelegate * delegate);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(MessagePortProvider);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_MESSAGE_PORT_PROVIDER_H_