change Paint input parameter to ref

Change-Id: I4bf97d46736ce8186c3699c9a861e44103ab0d4b

include/vcl/window.hxx

-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+y/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
  * This file is part of the LibreOffice project.
  *
@@ -702,7 +702,7 @@ public:
     virtual void                        KeyInput( const KeyEvent& rKEvt );
     virtual void                        KeyUp( const KeyEvent& rKEvt );
     virtual void                        PrePaint();
-    virtual void                        Paint(vcl::RenderContext* pRenderContext, const Rectangle& rRect);
+    virtual void                        Paint(vcl::RenderContext& rRenderContext, const Rectangle& rRect);
     virtual void                        Paint(const Rectangle& rRect);
     virtual void                        Erase() SAL_OVERRIDE;
     virtual void                        Erase( const Rectangle& rRect ) SAL_OVERRIDE { ::OutputDevice::Erase( rRect ); }

vcl/source/window/window.cxx

@@ -3927,7 +3927,7 @@ Any Window::GetSystemDataAny() const
     return aRet;
 }
 
-void Window::Paint(vcl::RenderContext* /*pRenderContext*/, const Rectangle& rRect)
+void Window::Paint(vcl::RenderContext& /*rRenderContext*/, const Rectangle& rRect)
 {
     Paint(rRect);
 }