Allow defining named grid lines on the grid element

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index e7629218b260fa54eba5ecd298b5b1310d39d513..44a943f80849416bbb2f1930842deee1cf4d0b6b 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -752,6 +752,8 @@ public:
 
     const Vector<GridTrackSize>& gridColumns() const { return rareNonInheritedData->m_grid->m_gridColumns; }
     const Vector<GridTrackSize>& gridRows() const { return rareNonInheritedData->m_grid->m_gridRows; }
+    const NamedGridLinesMapping& namedGridColumnLines() const { return rareNonInheritedData->m_grid->m_namedGridColumnLines; }
+    const NamedGridLinesMapping& namedGridRowLines() const { return rareNonInheritedData->m_grid->m_namedGridRowLines; }
     GridAutoFlow gridAutoFlow() const { return rareNonInheritedData->m_grid->m_gridAutoFlow; }
     const GridTrackSize& gridAutoColumns() const { return rareNonInheritedData->m_grid->m_gridAutoColumns; }
     const GridTrackSize& gridAutoRows() const { return rareNonInheritedData->m_grid->m_gridAutoRows; }
@@ -1207,6 +1209,8 @@ public:
     void setGridAutoRows(const GridTrackSize& length) { SET_VAR(rareNonInheritedData.access()->m_grid, m_gridAutoRows, length); }
     void setGridColumns(const Vector<GridTrackSize>& lengths) { SET_VAR(rareNonInheritedData.access()->m_grid, m_gridColumns, lengths); }
     void setGridRows(const Vector<GridTrackSize>& lengths) { SET_VAR(rareNonInheritedData.access()->m_grid, m_gridRows, lengths); }
+    void setNamedGridColumnLines(const NamedGridLinesMapping& namedGridColumnLines) { SET_VAR(rareNonInheritedData.access()->m_grid, m_namedGridColumnLines, namedGridColumnLines); }
+    void setNamedGridRowLines(const NamedGridLinesMapping& namedGridRowLines) { SET_VAR(rareNonInheritedData.access()->m_grid, m_namedGridRowLines, namedGridRowLines); }
     void setGridAutoFlow(GridAutoFlow flow) { SET_VAR(rareNonInheritedData.access()->m_grid, m_gridAutoFlow, flow); }
 
     void setGridStart(const GridPosition& startPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridStart, startPosition); }