Sync app order for extension items

chrome/browser/ui/app_list/extension_app_item.h

Index: chrome/browser/ui/app_list/extension_app_item.h
diff --git a/chrome/browser/ui/app_list/extension_app_item.h b/chrome/browser/ui/app_list/extension_app_item.h
index 3d4224f1a1d7704e823584ae901b01a68f8aabb2..eb56f42b32ef60c6764cef0d74e7ddb848402b61 100644
--- a/chrome/browser/ui/app_list/extension_app_item.h
+++ b/chrome/browser/ui/app_list/extension_app_item.h
@@ -48,6 +48,11 @@ class ExtensionAppItem : public app_list::AppListItemModel,
   // it gray.
   void UpdateIcon();
 
+  // Update page and app launcher ordinals to put the app in between |prev| and
+  // |next|. Note that |prev| and |next| could be NULL when the app is put at
+  // the beginning or at the end.
+  void Move(const ExtensionAppItem* prev, const ExtensionAppItem* next);
+
   const std::string& extension_id() const { return extension_id_; }
 
   static const char kAppType[];