Add shutdown widget.

src/windows/ShutdownWidget.h

@@ -0,0 +1,20 @@
+#ifndef SHUTDOWNWIDGET_H
+#define SHUTDOWNWIDGET_H
+
+#include <QWidget>
+
+class QLabel;
+class LoadingWidget;
+
+class ShutdownWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    ShutdownWidget(QWidget* aParent);
+
+private:
+    LoadingWidget* mLoadingWidget;
+    QLabel* mMessage;
+};
+
+#endif // SHUTDOWNWIDGET_H