DiffEditor: Use AsyncTask

Change-Id: Id5b21b10c7a8805b560eb4fb36fd955b7af34afa
Reviewed-by: hjk <hjk@qt.io>

src/plugins/diffeditor/unifieddiffeditorwidget.h

@@ -6,12 +6,17 @@
 #include "diffeditorwidgetcontroller.h"
 #include "selectabletexteditorwidget.h"
 
-#include <QFutureWatcher>
+#include <QFutureInterface>
 
 namespace Core { class IContext; }
 
 namespace TextEditor { class FontSettings; }
 
+namespace Utils {
+template <typename R>
+class AsyncTask;
+}
+
 namespace DiffEditor {
 
 class ChunkData;
@@ -107,7 +112,7 @@ private:
         DiffSelections selections;
     };
 
-    std::unique_ptr<QFutureWatcher<ShowResult>> m_watcher;
+    std::unique_ptr<Utils::AsyncTask<ShowResult>> m_asyncTask;
 };
 
 } // namespace Internal