Replace FOR_EACH_OBSERVER in c/b/chromeos with range-based for

chrome/browser/chromeos/login/session/user_session_manager.cc

Index: chrome/browser/chromeos/login/session/user_session_manager.cc
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.cc b/chrome/browser/chromeos/login/session/user_session_manager.cc
index dddb10455a9834e527daa093aaf9824287ffa60e..c653339d56a3be0155b1579726b0db919299295a 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.cc
+++ b/chrome/browser/chromeos/login/session/user_session_manager.cc
@@ -1529,9 +1529,8 @@ void UserSessionManager::NotifyPendingUserSessionsRestoreFinished() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   user_sessions_restored_ = true;
   user_sessions_restore_in_progress_ = false;
-  FOR_EACH_OBSERVER(chromeos::UserSessionStateObserver,
-                    session_state_observer_list_,
-                    PendingUserSessionsRestoreFinished());
+  for (auto& observer : session_state_observer_list_)
+    observer.PendingUserSessionsRestoreFinished();
 }
 
 void UserSessionManager::UpdateEasyUnlockKeys(const UserContext& user_context) {