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

remoting/signaling/fake_signal_strategy.cc

 // 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.
 
 #include "remoting/signaling/fake_signal_strategy.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 45 matching lines @@
                    base::Unretained(peer),
                    peer_callback));
   }
 }
 
 void FakeSignalStrategy::SetLocalJid(const std::string& jid) {
   DCHECK(CalledOnValidThread());
   jid_ = jid;
 }
 
+void FakeSignalStrategy::SimulatePackgeReordering() {
+  DCHECK(CalledOnValidThread());
+  simulate_reorder_ = true;
+}
+
 void FakeSignalStrategy::Connect() {
   DCHECK(CalledOnValidThread());
   for (auto& observer : listeners_)
     observer.OnSignalStrategyStateChange(CONNECTED);
 }
 
 void FakeSignalStrategy::Disconnect() {
   DCHECK(CalledOnValidThread());
   for (auto& observer : listeners_)
     observer.OnSignalStrategyStateChange(DISCONNECTED);
@@ skipping 52 matching lines @@
     std::unique_ptr<buzz::XmlElement> stanza) {
   thread->PostTask(FROM_HERE,
                    base::Bind(&FakeSignalStrategy::OnIncomingMessage,
                               target, base::Passed(&stanza)));
 }
 
 void FakeSignalStrategy::OnIncomingMessage(
     std::unique_ptr<buzz::XmlElement> stanza) {
   DCHECK(CalledOnValidThread());
 
+  if (!simulate_reorder_) {
+    NotifyListeners(std::move(stanza));
+    return;
+  }
+
+  // Simulate IQ messages re-ordering by swapping the delivery order of
+  // next pair of messages.
+  if (pending_stanza_) {
+    NotifyListeners(std::move(stanza));
+    NotifyListeners(std::move(pending_stanza_));
+    pending_stanza_.reset();
+  } else {
+    pending_stanza_ = std::move(stanza);
+  }
+}
+
+void FakeSignalStrategy::NotifyListeners(
+    std::unique_ptr<buzz::XmlElement> stanza) {
+  DCHECK(CalledOnValidThread());
+
   buzz::XmlElement* stanza_ptr = stanza.get();
   received_messages_.push_back(stanza.release());
 
   const std::string& to_field = stanza_ptr->Attr(buzz::QN_TO);
   if (to_field != jid_) {
     LOG(WARNING) << "Dropping stanza that is addressed to " << to_field
                  << ". Local jid: " << jid_
                  << ". Message content: " << stanza_ptr->Str();
     return;
   }
 
   for (auto& listener : listeners_) {
     if (listener.OnSignalStrategyIncomingStanza(stanza_ptr))
       break;
   }
 }
 
 void FakeSignalStrategy::SetPeerCallback(const PeerCallback& peer_callback) {
   peer_callback_ = peer_callback;
 }
 
 }  // namespace remoting