opengl dr.memory: DC that contains selected object being deleted.

Change-Id: I3cfb09eacfa129a92dace47fd26ccf6e5d1a6756

vcl/inc/win/salgdi.h

@@ -155,6 +155,9 @@ private:
     /// DIBSection that we use for the GDI drawing, and later obtain.
     HBITMAP mhBitmap;
 
+    /// Return the previous bitmap to undo the SelectObject.
+    HBITMAP mhOrigBitmap;
+
     /// DIBSection data.
     sal_uInt32 *mpData;
 

vcl/win/source/gdi/salgdi.cxx

@@ -582,13 +582,14 @@ OpenGLCompatibleDC::OpenGLCompatibleDC(SalGraphics &rGraphics, int x, int y, int
 
     mhBitmap = WinSalVirtualDevice::ImplCreateVirDevBitmap(mhCompatibleDC, width, height, 32, reinterpret_cast<void **>(&mpData));
 
-    SelectObject(mhCompatibleDC, mhBitmap);
+    mhOrigBitmap = (HBITMAP) SelectObject(mhCompatibleDC, mhBitmap);
 }
 
 OpenGLCompatibleDC::~OpenGLCompatibleDC()
 {
     if (mpImpl)
     {
+        SelectObject(mhCompatibleDC, mhOrigBitmap);
         DeleteObject(mhBitmap);
         DeleteDC(mhCompatibleDC);
     }