Save / restore state in diff editor when reloading

Task-number: QTCREATORBUG-12650
Change-Id: I0bb25ed39f8a15dd5da798ebf0ce72898a2e3b3d
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/diffeditor/diffeditorplugin.cpp

@@ -132,7 +132,9 @@ void SimpleDiffEditorReloader::reload()
     QList<FileData> fileDataList;
     fileDataList << fileData;
 
+    controller()->requestSaveState();
     controller()->setDiffFiles(fileDataList);
+    controller()->requestRestoreState();
 
     reloadFinished();
 }