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

content/browser/service_worker/embedded_worker_instance.cc

Index: content/browser/service_worker/embedded_worker_instance.cc
diff --git a/content/browser/service_worker/embedded_worker_instance.cc b/content/browser/service_worker/embedded_worker_instance.cc
index 842a57a357553eb9d6d591088973fd0bfc0b1306..8e81ee915edfcf7a3dc0c8a01fe186ef4f6338aa 100644
--- a/content/browser/service_worker/embedded_worker_instance.cc
+++ b/content/browser/service_worker/embedded_worker_instance.cc
@@ -775,9 +775,8 @@ base::WeakPtr<EmbeddedWorkerInstance> EmbeddedWorkerInstance::AsWeakPtr() {
 }
 
 bool EmbeddedWorkerInstance::OnMessageReceived(const IPC::Message& message) {
-  ListenerList::Iterator it(&listener_list_);
-  while (Listener* listener = it.GetNext()) {
-    if (listener->OnMessageReceived(message))
+  for (auto& listener : listener_list_) {
+    if (listener.OnMessageReceived(message))
       return true;
   }
   return false;