Reduce usage of FOR_EACH_OBSERVER macro in components/

components/wallpaper/wallpaper_manager_base.cc

Index: components/wallpaper/wallpaper_manager_base.cc
diff --git a/components/wallpaper/wallpaper_manager_base.cc b/components/wallpaper/wallpaper_manager_base.cc
index e0d38e34ad41ab8e692ff6cb46cf6b7e69bc2c41..9e2d233100edc862c4981c5e3a958a7d0b39505d 100644
--- a/components/wallpaper/wallpaper_manager_base.cc
+++ b/components/wallpaper/wallpaper_manager_base.cc
@@ -630,7 +630,8 @@ void WallpaperManagerBase::SetUserWallpaperNow(const AccountId& account_id) {
 }
 
 void WallpaperManagerBase::UpdateWallpaper(bool clear_cache) {
-  FOR_EACH_OBSERVER(Observer, observers_, OnUpdateWallpaperForTesting());
+  for (auto& observer : observers_)
+    observer.OnUpdateWallpaperForTesting();
   if (clear_cache)
     wallpaper_cache_.clear();
   SetUserWallpaperNow(last_selected_user_);
@@ -647,8 +648,8 @@ void WallpaperManagerBase::RemoveObserver(
 }
 
 void WallpaperManagerBase::NotifyAnimationFinished() {
-  FOR_EACH_OBSERVER(Observer, observers_,
-                    OnWallpaperAnimationFinished(last_selected_user_));
+  for (auto& observer : observers_)
+    observer.OnWallpaperAnimationFinished(last_selected_user_);
 }
 
 // WallpaperManager, protected: -----------------------------------------------