Move ownership of AppSorting from ExtensionPrefs to ExtensionSystem

extensions/browser/app_window/app_window_geometry_cache_unittest.cc

Index: extensions/browser/app_window/app_window_geometry_cache_unittest.cc
diff --git a/extensions/browser/app_window/app_window_geometry_cache_unittest.cc b/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
index e1f4068440298217262576b2c982b80a4972d15f..b35a5439cf7c2174faf8d10f240b943154b98d3f 100644
--- a/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
+++ b/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
@@ -17,7 +17,6 @@
 #include "extensions/browser/extension_pref_value_map.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extensions_test.h"
-#include "extensions/browser/null_app_sorting.h"
 #include "extensions/common/extension_builder.h"
 #include "extensions/common/value_builder.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -92,11 +91,9 @@ void AppWindowGeometryCacheTest::SetUp() {
   pref_service_ = factory.Create(pref_registry).Pass();
 
   extension_prefs_.reset(ExtensionPrefs::Create(
-      pref_service_.get(),
+      browser_context(), pref_service_.get(),
       browser_context()->GetPath().AppendASCII("Extensions"),
-      extension_pref_value_map_.get(),
-      scoped_ptr<AppSorting>(new NullAppSorting),
-      false /* extensions_disabled */,
+      extension_pref_value_map_.get(), false /* extensions_disabled */,
       std::vector<ExtensionPrefsObserver*>()));
 
   cache_.reset(