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

remoting/host/register_support_host_request_unittest.cc

Index: remoting/host/register_support_host_request_unittest.cc
diff --git a/remoting/host/register_support_host_request_unittest.cc b/remoting/host/register_support_host_request_unittest.cc
index 9bcfb9dba656d088fb6243dd8fa368a7853803be..a467476c4742070658ebc7e2e885f7a49b57846d 100644
--- a/remoting/host/register_support_host_request_unittest.cc
+++ b/remoting/host/register_support_host_request_unittest.cc
@@ -153,11 +153,8 @@ TEST_F(RegisterSupportHostRequestTest, Send) {
   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);