Move ExtensionSystem into extensions namespace

chrome/browser/sync/profile_sync_components_factory_impl.h

Index: chrome/browser/sync/profile_sync_components_factory_impl.h
diff --git a/chrome/browser/sync/profile_sync_components_factory_impl.h b/chrome/browser/sync/profile_sync_components_factory_impl.h
index ec7a46a97febb6f1e07be7003d55ea7a62a20364..241cc8f711c458900c290cae7e1e24b9e17a92d4 100644
--- a/chrome/browser/sync/profile_sync_components_factory_impl.h
+++ b/chrome/browser/sync/profile_sync_components_factory_impl.h
@@ -13,9 +13,12 @@
 #include "chrome/browser/webdata/web_data_service.h"
 
 class CommandLine;
-class ExtensionSystem;
 class Profile;
 
+namespace extensions {
+class ExtensionSystem;
+}
+
 class ProfileSyncComponentsFactoryImpl : public ProfileSyncComponentsFactory {
  public:
   ProfileSyncComponentsFactoryImpl(Profile* profile,
@@ -63,9 +66,10 @@ class ProfileSyncComponentsFactoryImpl : public ProfileSyncComponentsFactory {
  private:
   Profile* profile_;
   CommandLine* command_line_;
-  // Set on the UI thread (since ExtensionSystemFactory is non-threadsafe);
-  // accessed on both the UI and FILE threads in GetSyncableServiceForType.
-  ExtensionSystem* extension_system_;
+  // Set on the UI thread (since extensions::ExtensionSystemFactory is
+  // non-threadsafe); accessed on both the UI and FILE threads in
+  // GetSyncableServiceForType.
+  extensions::ExtensionSystem* extension_system_;
   scoped_refptr<WebDataService> web_data_service_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncComponentsFactoryImpl);