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

chrome/browser/platform_apps/platform_app_service_factory.h

Index: chrome/browser/platform_apps/platform_app_service_factory.h
diff --git a/chrome/browser/extensions/platform_app_service_factory.h b/chrome/browser/platform_apps/platform_app_service_factory.h
similarity index 75%
rename from chrome/browser/extensions/platform_app_service_factory.h
rename to chrome/browser/platform_apps/platform_app_service_factory.h
index 82412e92dbd849bd3a3305124c828cd9f66e8290..ea5d87994c309d2dcdffa92cc5e0dae15b123cc6 100644
--- a/chrome/browser/extensions/platform_app_service_factory.h
+++ b/chrome/browser/platform_apps/platform_app_service_factory.h
@@ -2,15 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_SERVICE_FACTORY_H_
-#define CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_SERVICE_FACTORY_H_
+#ifndef CHROME_BROWSER_PLATFORM_APPS_PLATFORM_APP_SERVICE_FACTORY_H_
+#define CHROME_BROWSER_PLATFORM_APPS_PLATFORM_APP_SERVICE_FACTORY_H_
 
 #include "base/memory/singleton.h"
-#include "chrome/browser/extensions/platform_app_service.h"
+#include "chrome/browser/platform_apps/platform_app_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
 
-namespace extensions {
+namespace platform_apps {
 
 class PlatformAppServiceFactory : public ProfileKeyedServiceFactory {
  public:
@@ -31,6 +31,6 @@ class PlatformAppServiceFactory : public ProfileKeyedServiceFactory {
   virtual bool ServiceIsNULLWhileTesting() const OVERRIDE;
 };
 
-}  // namespace extensions
+}  // namespace platform_apps
 
-#endif  // CHROME_BROWSER_EXTENSIONS_PLATFORM_APP_SERVICE_FACTORY_H_
+#endif  // CHROME_BROWSER_PLATFORM_APPS_PLATFORM_APP_SERVICE_FACTORY_H_