Cleanup: Remove LayoutRegion.

Source/core/paint/MultiColumnSetPainter.cpp

Index: Source/core/paint/MultiColumnSetPainter.cpp
diff --git a/Source/core/paint/MultiColumnSetPainter.cpp b/Source/core/paint/MultiColumnSetPainter.cpp
index c6ab0d3cf7e3fa06e1fa539e0836154bfd208b78..ad32ee3feab2784f68e20851b112d214c839011b 100644
--- a/Source/core/paint/MultiColumnSetPainter.cpp
+++ b/Source/core/paint/MultiColumnSetPainter.cpp
@@ -26,7 +26,7 @@ void MultiColumnSetPainter::paintObject(const PaintInfo& paintInfo, const Layout
     // LayoutBlocks do. Note this is a pretty minor issue, since the old column implementation clipped columns
     // anyway, thus making it impossible for them to overlap one another. It's also really unlikely that the columns
     // would overlap another block.
-    if (!m_layoutMultiColumnSet.flowThread() || !m_layoutMultiColumnSet.isValid() || (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseSelection))
+    if (!m_layoutMultiColumnSet.flowThread() || (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseSelection))
         return;
 
     paintColumnRules(paintInfo, paintOffset);