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

chrome/browser/platform_apps/platform_app_service_factory.cc

Index: chrome/browser/platform_apps/platform_app_service_factory.cc
diff --git a/chrome/browser/extensions/platform_app_service_factory.cc b/chrome/browser/platform_apps/platform_app_service_factory.cc
similarity index 90%
rename from chrome/browser/extensions/platform_app_service_factory.cc
rename to chrome/browser/platform_apps/platform_app_service_factory.cc
index c4fa6d1d2a4c6a4d4e91c697ef3f481fbe5ccac7..b36ce54719125bd1514d8f3d21ecd3d597bd17ba 100644
--- a/chrome/browser/extensions/platform_app_service_factory.cc
+++ b/chrome/browser/platform_apps/platform_app_service_factory.cc
@@ -2,11 +2,11 @@
 // 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(
@@ -44,4 +44,4 @@ bool PlatformAppServiceFactory::ServiceIsNULLWhileTesting() const {
   return false;
 }
 
-}  // namespace extensions
+}  // namespace platform_apps