Separate the NTP app ordering from the app list app ordering

chrome/browser/extensions/extension_ordering.cc

Index: chrome/browser/extensions/extension_ordering.cc
diff --git a/chrome/browser/extensions/extension_ordering.cc b/chrome/browser/extensions/extension_ordering.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a81016684a2bfcafa4b13eba98e7a255dedce8df
--- /dev/null
+++ b/chrome/browser/extensions/extension_ordering.cc
@@ -0,0 +1,42 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/extension_ordering.h"
+
+#include "base/prefs/pref_service.h"
+#include "chrome/browser/extensions/extension_prefs.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+
+ExtensionOrdering::ExtensionOrdering(
+    ExtensionScopedPrefs* extension_scoped_prefs)
+    : extension_scoped_prefs_(extension_scoped_prefs),
+      extension_service_(NULL) {
+}
+
+ExtensionOrdering::~ExtensionOrdering() {
+}
+
+void ExtensionOrdering::SetExtensionService(
+    ExtensionServiceInterface* extension_service) {
+  extension_service_ = extension_service;
+}
+
+void ExtensionOrdering::SyncIfNeeded(const std::string& extension_id) {
+  if (!extension_service_)
+    NOTREACHED();
+
+  const extensions::Extension* extension =
+      extension_service_->GetInstalledExtension(extension_id);
+
+  if (extension) {
+    // It is possible for non-app extensions to have ordinal values, but they
+    // shouldn't so we clear them.
+    if (!extension->is_app())
+      Erase(extension_id);
+
+    extension_service_->SyncExtensionChangeIfNeeded(*extension);
+  }
+}