Reduce FOR_EACH_OBSERVER usage in extensions

extensions/browser/warning_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/warning_service.h"
 
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extensions_browser_client.h"
 #include "extensions/browser/warning_service_factory.h"
@@ skipping 99 matching lines @@
 void WarningService::AddObserver(Observer* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void WarningService::RemoveObserver(Observer* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
 void WarningService::NotifyWarningsChanged(
     const ExtensionIdSet& affected_extensions) {
-  FOR_EACH_OBSERVER(Observer, observer_list_,
-                    ExtensionWarningsChanged(affected_extensions));
+  for (auto& observer : observer_list_)
+    observer.ExtensionWarningsChanged(affected_extensions);
 }
 
 void WarningService::OnExtensionUnloaded(
     content::BrowserContext* browser_context,
     const Extension* extension,
     UnloadedExtensionInfo::Reason reason) {
   // Unloading one extension might have solved the problems of others.
   // Therefore, we clear warnings of this type for all extensions.
   std::set<Warning::WarningType> warning_types =
       GetWarningTypesAffectingExtension(extension->id());
   ClearWarnings(warning_types);
 }
 
 }  // namespace extensions