Reduce usage of FOR_EACH_OBSERVER macro in content/

content/child/worker_thread_registry.cc

Index: content/child/worker_thread_registry.cc
diff --git a/content/child/worker_thread_registry.cc b/content/child/worker_thread_registry.cc
index cfc9d837b503333ee8349e095ed9bc02fad1b214..f3d6fc5b3e5216b7eca667bc0fdd5fa04952cf1d 100644
--- a/content/child/worker_thread_registry.cc
+++ b/content/child/worker_thread_registry.cc
@@ -107,8 +107,9 @@ void WorkerThreadRegistry::DidStartCurrentWorkerThread() {
 void WorkerThreadRegistry::WillStopCurrentWorkerThread() {
   WorkerThreadObservers* observers = g_observers_tls.Pointer()->Get();
   DCHECK(observers);
-  FOR_EACH_OBSERVER(WorkerThread::Observer, *observers,
-                    WillStopCurrentWorkerThread());
+  for (auto& observer : *observers)
+    observer.WillStopCurrentWorkerThread();
+
   {
     base::AutoLock locker(task_runner_map_lock_);
     task_runner_map_.erase(WorkerThread::GetCurrentId());