Move ownership of AppSorting from ExtensionPrefs to ExtensionSystem

extensions/browser/extension_prefs_factory.cc

Index: extensions/browser/extension_prefs_factory.cc
diff --git a/extensions/browser/extension_prefs_factory.cc b/extensions/browser/extension_prefs_factory.cc
index 5908000e5c2bb06a3b443c836b4123b75d4c470c..e9811cee109d66758bf11e7e4a958605ae9d1efd 100644
--- a/extensions/browser/extension_prefs_factory.cc
+++ b/extensions/browser/extension_prefs_factory.cc
@@ -30,6 +30,7 @@ ExtensionPrefsFactory* ExtensionPrefsFactory::GetInstance() {
 void ExtensionPrefsFactory::SetInstanceForTesting(
     content::BrowserContext* context,
     scoped_ptr<ExtensionPrefs> prefs) {
+  Disassociate(context);
   Associate(context, prefs.Pass());
 }
 
@@ -51,7 +52,6 @@ KeyedService* ExtensionPrefsFactory::BuildServiceInstanceFor(
       client->GetPrefServiceForContext(context),
       context->GetPath().AppendASCII(extensions::kInstallDirectoryName),
       ExtensionPrefValueMapFactory::GetForBrowserContext(context),
-      client->CreateAppSorting(context).Pass(),
       client->AreExtensionsDisabled(*base::CommandLine::ForCurrentProcess(),
                                     context),
       prefs_observers);