Remove usage of base::ObserverList<T>::Iter::GetNext() in //remoting.

remoting/host/register_support_host_request_unittest.cc

 // Copyright (c) 2012 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/host/register_support_host_request.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
@@ skipping 135 matching lines @@
       QName(kChromotingXmlNamespace, "support-id"));
   support_id->AddText(kSupportId);
   result->AddElement(support_id);
 
   XmlElement* support_id_lifetime = new XmlElement(
       QName(kChromotingXmlNamespace, "support-id-lifetime"));
   support_id_lifetime->AddText(kSupportIdLifetime);
   result->AddElement(support_id_lifetime);
 
   int consumed = 0;
-  base::ObserverListBase<SignalStrategy::Listener>::Iterator it(
-      &signal_strategy_listeners_);
-  SignalStrategy::Listener* listener;
-  while ((listener = it.GetNext()) != nullptr) {
-    if (listener->OnSignalStrategyIncomingStanza(response.get()))
+  for (auto& listener : signal_strategy_listeners_) {
+    if (listener.OnSignalStrategyIncomingStanza(response.get()))
       consumed++;
   }
   EXPECT_EQ(1, consumed);
 
   base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace remoting