Skip all Context2D handling if not needed.
Skip all Context2D handling if not needed.

The GL2PS Exporter currently creates the ContextDevice2D regardless
of whether or not any Context2D drawing is used. This patch fixes this.

Change-Id: If0d6318450a45f27cc3a9f2470f72e5db4cd161a

msmolens/VTK,msmolens/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,collects/VTK,candy7393/VTK,collects/VTK,sankhesh/VTK,msmolens/VTK,demarle/VTK,jmerkow/VTK,sankhesh/VTK,keithroe/vtkoptix,candy7393/VTK,sumedhasingla/VTK,jmerkow/VTK,jmerkow/VTK,SimVascular/VTK,ashray/VTK-EVM,SimVascular/VTK,hendradarwin/VTK,hendradarwin/VTK,SimVascular/VTK,collects/VTK,hendradarwin/VTK,biddisco/VTK,keithroe/vtkoptix,demarle/VTK,sankhesh/VTK,biddisco/VTK,demarle/VTK,candy7393/VTK,aashish24/VTK-old,msmolens/VTK,mspark93/VTK,mspark93/VTK,aashish24/VTK-old,gram526/VTK,jmerkow/VTK,ashray/VTK-EVM,sumedhasingla/VTK,demarle/VTK,sumedhasingla/VTK,keithroe/vtkoptix,hendradarwin/VTK,jmerkow/VTK,msmolens/VTK,candy7393/VTK,jmerkow/VTK,mspark93/VTK,biddisco/VTK,johnkit/vtk-dev,gram526/VTK,collects/VTK,msmolens/VTK,keithroe/vtkoptix,berendkleinhaneveld/VTK,ashray/VTK-EVM,sankhesh/VTK,collects/VTK,sumedhasingla/VTK,johnkit/vtk-dev,mspark93/VTK,hendradarwin/VTK,biddisco/VTK,ashray/VTK-EVM,SimVascular/VTK,berendkleinhaneveld/VTK,msmolens/VTK,gram526/VTK,mspark93/VTK,candy7393/VTK,SimVascular/VTK,gram526/VTK,gram526/VTK,berendkleinhaneveld/VTK,biddisco/VTK,johnkit/vtk-dev,aashish24/VTK-old,biddisco/VTK,aashish24/VTK-old,sankhesh/VTK,demarle/VTK,keithroe/vtkoptix,keithroe/vtkoptix,msmolens/VTK,berendkleinhaneveld/VTK,demarle/VTK,demarle/VTK,collects/VTK,biddisco/VTK,candy7393/VTK,sumedhasingla/VTK,aashish24/VTK-old,mspark93/VTK,mspark93/VTK,sankhesh/VTK,mspark93/VTK,ashray/VTK-EVM,sumedhasingla/VTK,SimVascular/VTK,jmerkow/VTK,gram526/VTK,keithroe/vtkoptix,candy7393/VTK,johnkit/vtk-dev,sumedhasingla/VTK,ashray/VTK-EVM,candy7393/VTK,hendradarwin/VTK,ashray/VTK-EVM,sumedhasingla/VTK,berendkleinhaneveld/VTK,johnkit/vtk-dev,gram526/VTK,johnkit/vtk-dev,sankhesh/VTK,johnkit/vtk-dev,ashray/VTK-EVM,gram526/VTK,jmerkow/VTK,keithroe/vtkoptix,demarle/VTK,aashish24/VTK-old,hendradarwin/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,sankhesh/VTK