Reduce usage of FOR_EACH_OBSERVER macro in components/invalidation

components/invalidation/impl/ticl_settings_provider.cc

Index: components/invalidation/impl/ticl_settings_provider.cc
diff --git a/components/invalidation/impl/ticl_settings_provider.cc b/components/invalidation/impl/ticl_settings_provider.cc
index 6c9c6327d1b14c16662a80044cff25a4e3e889b1..c8b7adc535d1cdcf38d40d1ac6bc37c4d06bc5d1 100644
--- a/components/invalidation/impl/ticl_settings_provider.cc
+++ b/components/invalidation/impl/ticl_settings_provider.cc
@@ -24,7 +24,8 @@ void TiclSettingsProvider::RemoveObserver(Observer* observer) {
 }
 
 void TiclSettingsProvider::FireOnUseGCMChannelChanged() {
-  FOR_EACH_OBSERVER(Observer, observers_, OnUseGCMChannelChanged());
+  for (auto& observer : observers_)
+    observer.OnUseGCMChannelChanged();
 }
 
 }  // namespace invalidation