Remove FOR_EACH_OBSERVER macro usage in chrome/browser/sync_file_system

chrome/browser/sync_file_system/drive_backend/sync_engine.cc

Index: chrome/browser/sync_file_system/drive_backend/sync_engine.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
index f0f9acf98b9c780a4c4a494f5f02ecd781d9673b..42a601594598c1ecd0315a81e4c0351201c4565a 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
+++ b/chrome/browser/sync_file_system/drive_backend/sync_engine.cc
@@ -748,10 +748,8 @@ SyncEngine::SyncEngine(
 }
 
 void SyncEngine::OnPendingFileListUpdated(int item_count) {
-  FOR_EACH_OBSERVER(
-      SyncServiceObserver,
-      service_observers_,
-      OnRemoteChangeQueueUpdated(item_count));
+  for (auto& observer : service_observers_)
+    observer.OnRemoteChangeQueueUpdated(item_count);
 }
 
 void SyncEngine::OnFileStatusChanged(const storage::FileSystemURL& url,
@@ -759,19 +757,18 @@ void SyncEngine::OnFileStatusChanged(const storage::FileSystemURL& url,
                                      SyncFileStatus file_status,
                                      SyncAction sync_action,
                                      SyncDirection direction) {
-  FOR_EACH_OBSERVER(FileStatusObserver,
-                    file_status_observers_,
-                    OnFileStatusChanged(
-                        url, file_type, file_status, sync_action, direction));
+  for (auto& observer : file_status_observers_) {
+    observer.OnFileStatusChanged(url, file_type, file_status, sync_action,
+                                 direction);
+  }
 }
 
 void SyncEngine::UpdateServiceState(RemoteServiceState state,
                                     const std::string& description) {
   service_state_ = state;
 
-  FOR_EACH_OBSERVER(
-      SyncServiceObserver, service_observers_,
-      OnRemoteServiceStateUpdated(GetCurrentState(), description));
+  for (auto& observer : service_observers_)
+    observer.OnRemoteServiceStateUpdated(GetCurrentState(), description);
 }
 
 SyncStatusCallback SyncEngine::TrackCallback(