vcl: remove IOS/OSX only code

Change-Id: I83fd835a8a198ff469cfaa0441c938acf9433862
Reviewed-on: https://gerrit.libreoffice.org/13206Reviewed-by: Chris Sherlock <chris.sherlock79@gmail.com>
Tested-by: Chris Sherlock <chris.sherlock79@gmail.com>

vcl/inc/headless/svpgdi.hxx

@@ -202,8 +202,6 @@ public:
 
     virtual void            BeginPaint() SAL_OVERRIDE { };
     virtual void            EndPaint() SAL_OVERRIDE { };
-
-    void                SetVirDevGraphics( CGLayerRef xLayer, CGContextRef xContext, int = 0 );
 };
 
 #endif