useRegionBasedColumns  326 Source/core/rendering/RenderLayer.cpp     if (useRegionBasedColumns() && renderer()->isInFlowRenderFlowThread()) {
useRegionBasedColumns  664 Source/core/rendering/RenderLayer.cpp     bool regionBasedColumnsUsed = useRegionBasedColumns();
useRegionBasedColumns  666 Source/core/rendering/RenderLayer.h     bool useRegionBasedColumns() const;