Merge topic 'cocoa_render_fix'

75f66072 Fix an issue with cocoa windows being grey

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6463

Rendering/OpenGL2/vtkCocoaRenderWindowInteractor.mm

@@ -265,6 +265,7 @@ void vtkCocoaRenderWindowInteractor::Initialize()
   // get the info we need from the RenderingWindow
   vtkCocoaRenderWindow* renWin = (vtkCocoaRenderWindow*)(this->RenderWindow);
   renWin->Start();
+  renWin->End();
   const int* size = renWin->GetSize();
 
   renWin->GetPosition(); // update values of this->Position[2]