implement virtual destructor in QPlatformSurface

Change-Id: Iaadd9c3cd7c2e2022066ca859cbe1e912050c561
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

src/gui/kernel/qplatformsurface_qpa.cpp

@@ -43,6 +43,11 @@
 
 QT_BEGIN_NAMESPACE
 
+QPlatformSurface::~QPlatformSurface()
+{
+
+}
+
 QSurface::SurfaceClass QPlatformSurface::surfaceClass() const
 {
     return m_type;

src/gui/kernel/qplatformsurface_qpa.h

@@ -54,6 +54,7 @@ QT_BEGIN_NAMESPACE
 class Q_GUI_EXPORT QPlatformSurface
 {
 public:
+    virtual ~QPlatformSurface();
     virtual QSurfaceFormat format() const = 0;
 
     QSurface::SurfaceClass surfaceClass() const;