cleanup: Use EventRouter instead of ExtensionSystem::Get->event_router()

chrome/browser/extensions/api/preference/preference_helpers.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 "chrome/browser/extensions/api/preference/preference_helpers.h"
 
 #include "base/json/json_writer.h"
 #include "base/prefs/pref_service.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/api/preference/preference_api.h"
@@ skipping 71 matching lines @@
   return kControlledByOtherExtensions;
 }
 
 void DispatchEventToExtensions(
     Profile* profile,
     const std::string& event_name,
     base::ListValue* args,
     APIPermission::ID permission,
     bool incognito,
     const std::string& browser_pref) {
-  EventRouter* router =
-      ExtensionSystem::Get(profile)->event_router();
+  EventRouter* router = EventRouter::Get(profile);
   if (!router || !router->HasEventListener(event_name))
     return;
   ExtensionService* extension_service =
       ExtensionSystem::Get(profile)->extension_service();
   const ExtensionSet* extensions = extension_service->extensions();
   for (ExtensionSet::const_iterator it = extensions->begin();
        it != extensions->end(); ++it) {
     std::string extension_id = (*it)->id();
     // TODO(bauerb): Only iterate over registered event listeners.
     if (router->ExtensionHasEventListener(extension_id, event_name) &&
@@ skipping 31 matching lines @@
       scoped_ptr<base::ListValue> args_copy(args->DeepCopy());
       scoped_ptr<Event> event(new Event(event_name, args_copy.Pass()));
       event->restrict_to_browser_context = restrict_to_profile;
       router->DispatchEventToExtension(extension_id, event.Pass());
     }
   }
 }
 
 }  // namespace preference_helpers
 }  // namespace extensions