plugins/windowsystem: Implement new virtuals

For XDG foreign support. No-ops.

src/plugins/windowsystem/windowsystem.cpp

@@ -67,6 +67,22 @@ quint32 WindowSystem::lastInputSerial(QWindow *window)
     }
     return w->lastUsageSerial();
 }
+
+void WindowSystem::exportWindow(QWindow *window)
+{
+    Q_UNUSED(window);
+}
+
+void WindowSystem::unexportWindow(QWindow *window)
+{
+    Q_UNUSED(window);
+}
+
+void WindowSystem::setMainWindow(QWindow *window, const QString &handle)
+{
+    Q_UNUSED(window);
+    Q_UNUSED(handle);
+}
 }
 
 #include "moc_windowsystem.cpp"

src/plugins/windowsystem/windowsystem.h

@@ -23,6 +23,9 @@ public:
     void requestToken(QWindow *win, uint32_t serial, const QString &app_id) override;
     void setCurrentToken(const QString &token) override;
     quint32 lastInputSerial(QWindow *window) override;
+    void exportWindow(QWindow *window) override;
+    void unexportWindow(QWindow *window) override;
+    void setMainWindow(QWindow *window, const QString &handle) override;
 };
 
 }