Optimized ComputeBounds.
Optimized ComputeBounds.

ComputeBounds was unnecessarily slow. Improved.

Change-Id: Id3453e7362bb0f18f362be2139dc3c90f80b3dff

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