DiffEditorController: Aggregate reloadRecipe

Instead of declaring virtual getter.

Change-Id: I0f9e995bdff1b7e387e71daaf149a3726b7c09af
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/diffeditor/diffeditorcontroller.h

@@ -61,6 +61,8 @@ protected:
     void setDisplayName(const QString &name) { m_displayName = name; }
     QString displayName() const { return m_displayName; }
 
+    void setReloadRecipe(const Utils::Tasking::Group &recipe) { m_reloadRecipe = recipe; }
+
     // reloadFinished() should be called inside the reloader (for synchronous reload)
     // or later (for asynchronous reload)
     void setReloader(const std::function<void ()> &reloader);
@@ -78,7 +80,7 @@ private:
     QString m_displayName;
     std::function<void()> m_reloader;
     std::unique_ptr<Utils::TaskTree> m_taskTree;
-    virtual Utils::Tasking::Group reloadRecipe() { return {}; } // TODO: make pure abstract
+    Utils::Tasking::Group m_reloadRecipe;
 
     friend class Internal::DiffEditorDocument;
 };