Process incoming IQs in the same order that they were sent.

remoting/protocol/jingle_session.h

Index: remoting/protocol/jingle_session.h
diff --git a/remoting/protocol/jingle_session.h b/remoting/protocol/jingle_session.h
index 0c16edfe4d84b86123d0f19887dc7ea8bd93ef71..26e2381f69617a9543c8dd02438799196941e3d6 100644
--- a/remoting/protocol/jingle_session.h
+++ b/remoting/protocol/jingle_session.h
@@ -18,6 +18,7 @@
 #include "remoting/protocol/authenticator.h"
 #include "remoting/protocol/datagram_channel_factory.h"
 #include "remoting/protocol/jingle_messages.h"
+#include "remoting/protocol/ordered_message_queue.h"
 #include "remoting/protocol/session.h"
 #include "remoting/protocol/session_config.h"
 #include "remoting/signaling/iq_sender.h"
@@ -81,9 +82,15 @@ class JingleSession : public Session {
   // Called by JingleSessionManager on incoming |message|. Must call
   // |reply_callback| to send reply message before sending any other
   // messages.
-  void OnIncomingMessage(std::unique_ptr<JingleMessage> message,
+  void OnIncomingMessage(std::string id,
+                         std::unique_ptr<JingleMessage> message,
                          const ReplyCallback& reply_callback);
 
+  // Called by OnIncomingMessage() to process the incoming Jingle messages
+  // in the same order that they are sent.
+  void OnIncomingMessageInOrder(std::unique_ptr<JingleMessage> message,
+                                     const ReplyCallback& reply_callback);
+
   // Message handlers for incoming messages.
   void OnAccept(std::unique_ptr<JingleMessage> message,
                 const ReplyCallback& reply_callback);
@@ -135,6 +142,17 @@ class JingleSession : public Session {
   // Pending transport-info requests.
   std::list<std::unique_ptr<IqRequest>> transport_info_requests_;
 
+  struct QueueItem {
+    QueueItem(std::unique_ptr<JingleMessage> message,
+              const ReplyCallback& reply_callback);
+    ~QueueItem();
+    std::unique_ptr<JingleMessage> message;
+    const ReplyCallback reply_callback;
+  };
+
+  // A message queue to guarantee the incoming messages are processed in order.
+  OrderedMessageQueue<std::unique_ptr<QueueItem>> message_queue_;
+
   base::WeakPtrFactory<JingleSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(JingleSession);