Reduce usage of FOR_EACH_OBSERVER macro in components/

components/zoom/zoom_event_manager.cc

Index: components/zoom/zoom_event_manager.cc
diff --git a/components/zoom/zoom_event_manager.cc b/components/zoom/zoom_event_manager.cc
index 5c328940cfed23afbe6229ac9bdde09b63618a2d..c1fd61cdd7315b9a55fa8dc24d51cc96f4469221 100644
--- a/components/zoom/zoom_event_manager.cc
+++ b/components/zoom/zoom_event_manager.cc
@@ -37,8 +37,8 @@ ZoomEventManager::AddZoomLevelChangedCallback(
 }
 
 void ZoomEventManager::OnDefaultZoomLevelChanged() {
-  FOR_EACH_OBSERVER(ZoomEventManagerObserver, observers_,
-                    OnDefaultZoomLevelChanged());
+  for (auto& observer : observers_)
+    observer.OnDefaultZoomLevelChanged();
 }
 
 void ZoomEventManager::AddZoomEventManagerObserver(