Reinitialize GL3D renderer when OpenGL window is changed

Without it when we switch sheets in Calc or slides in Impress
and go back to that page where the GL3DBar chart is then the
renderer does not work.

Change-Id: I9aa6203ed5aa7f94627d886b2f2e5ad34d493843

chart2/source/view/charttypes/GL3DBarChart.cxx

@@ -1313,7 +1313,14 @@ IMPL_LINK_NOARG(GL3DBarChart, updateTimer)
 void GL3DBarChart::setOpenGLWindow(OpenGLWindow* pWindow)
 {
     if (mpWindow != pWindow)
+    {
         mpWindow = pWindow;
+        Size aSize = mpWindow->GetSizePixel();
+        mpRenderer->SetSize(aSize);
+        mpWindow->setRenderer(this);
+        mpRenderer->init();
+        mbValidContext = true;
+    }
 }
 
 }