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

remoting/signaling/fake_signal_strategy.cc

Index: remoting/signaling/fake_signal_strategy.cc
diff --git a/remoting/signaling/fake_signal_strategy.cc b/remoting/signaling/fake_signal_strategy.cc
index 12cd2c12ffdd78aca62cadee1bc5d760894983d5..69af43d7ba14521f358ec19a8093b614836a75ae 100644
--- a/remoting/signaling/fake_signal_strategy.cc
+++ b/remoting/signaling/fake_signal_strategy.cc
@@ -146,10 +146,8 @@ void FakeSignalStrategy::OnIncomingMessage(
     return;
   }
 
-  base::ObserverListBase<Listener>::Iterator it(&listeners_);
-  Listener* listener;
-  while ((listener = it.GetNext()) != nullptr) {
-    if (listener->OnSignalStrategyIncomingStanza(stanza_ptr))
+  for (auto& listener : listeners_) {
+    if (listener.OnSignalStrategyIncomingStanza(stanza_ptr))
       break;
   }
 }