Create a new chrome/browser/apps folder and move PlatformAppService there.

chrome/browser/platform_apps/platform_app_service_factory.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/platform_app_service_factory.h"
+#include "chrome/browser/platform_apps/platform_app_service_factory.h"
 
 #include "chrome/browser/profiles/profile_dependency_manager.h"
 
-namespace extensions {
+namespace platform_apps {
 
 // static
 PlatformAppService* PlatformAppServiceFactory::GetForProfile(
     Profile* profile) {
   return static_cast<PlatformAppService*>(
       GetInstance()->GetServiceForProfile(profile, true));
 }
 
 PlatformAppServiceFactory* PlatformAppServiceFactory::GetInstance() {
   return Singleton<PlatformAppServiceFactory>::get();
@@ skipping 17 matching lines @@
 }
 
 bool PlatformAppServiceFactory::ServiceIsCreatedWithProfile() const {
   return true;
 }
 
 bool PlatformAppServiceFactory::ServiceIsNULLWhileTesting() const {
   return false;
 }
 
-}  // namespace extensions
+}  // namespace platform_apps