Avoid displaying offscreen render windows by not setting them as key.
Avoid displaying offscreen render windows by not setting them as key.

Change-Id: I6affb601590201eb6017c2dd465016b89a518aeb

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