Made varied number of cells in each row based on row's requirement.

third_party/WebKit/Source/core/layout/LayoutTableSection.h

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2009, 2013 Apple Inc. All rights
  * reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 200 matching lines @@
   const LayoutTableCell* firstRowCellAdjoiningTableStart() const;
   const LayoutTableCell* firstRowCellAdjoiningTableEnd() const;
 
   CellStruct& cellAt(unsigned row, unsigned effectiveColumn) {
     return m_grid[row].row[effectiveColumn];
   }
   const CellStruct& cellAt(unsigned row, unsigned effectiveColumn) const {
     return m_grid[row].row[effectiveColumn];
   }
   LayoutTableCell* primaryCellAt(unsigned row, unsigned effectiveColumn) {
+    if (effectiveColumn >= numCols(row))
+      return nullptr;
     CellStruct& c = m_grid[row].row[effectiveColumn];
     return c.primaryCell();
   }
   const LayoutTableCell* primaryCellAt(unsigned row,
                                        unsigned effectiveColumn) const {
     return const_cast<LayoutTableSection*>(this)->primaryCellAt(
         row, effectiveColumn);
   }
 
+  unsigned numCols(unsigned row) const { return m_grid[row].row.size(); }
+
   // Returns null for cells with a rowspan that exceed the last row. Possibly
   // others.
   LayoutTableRow* rowLayoutObjectAt(unsigned row) {
     return m_grid[row].rowLayoutObject;
   }
   const LayoutTableRow* rowLayoutObjectAt(unsigned row) const {
     return m_grid[row].rowLayoutObject;
   }
 
   void appendEffectiveColumn(unsigned pos);
@@ skipping 98 matching lines @@
   }
 
   void willBeRemovedFromTree() override;
 
   void layout() override;
 
   int borderSpacingForRow(unsigned row) const {
     return m_grid[row].rowLayoutObject ? table()->vBorderSpacing() : 0;
   }
 
-  void ensureRows(unsigned);
+  void ensureRows(unsigned numRows) {
+    if (numRows > m_grid.size())
+      m_grid.grow(numRows);
+  }
+
+  void ensureCols(unsigned rowIndex, unsigned numCols) {
+    if (numCols > this->numCols(rowIndex))
+      m_grid[rowIndex].row.grow(numCols);
+  }
 
   bool rowHasOnlySpanningCells(unsigned);
   unsigned calcRowHeightHavingOnlySpanningCells(unsigned,
                                                 int&,
                                                 unsigned,
                                                 unsigned&,
                                                 Vector<int>&);
   void updateRowsHeightHavingOnlySpanningCells(LayoutTableCell*,
                                                struct SpanningRowsHeight&,
                                                unsigned&,
@@ skipping 104 matching lines @@
   // The use is to disable a painting optimization where we just paint the
   // invalidated cells.
   bool m_hasMultipleCellLevels;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTableSection, isTableSection());
 
 }  // namespace blink
 
 #endif  // LayoutTableSection_h