Adds qt migration example

qt5-before/qt5-legacy-migration-benchmark/MainWindow.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <QMainWindow>
+#include <QRegExp>
+
+QT_BEGIN_NAMESPACE
+namespace Ui {
+class MainWindow;
+}
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    explicit MainWindow(QWidget *parent = 0);
+    ~MainWindow();
+
+private slots:
+    void onValidateClicked();
+    void onScreenInfoClicked();
+
+private:
+    Ui::MainWindow *ui;
+    QRegExp legacyPattern;
+};