Fix handling of 'inherit' and 'initial' for grid lines

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 7da1322377d30b3badaa09beb32d123710db55f5..8f79ddc0bd86052d35647a5a0687c9fc36be9fb3 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -769,10 +769,10 @@ public:
     const GridTrackSize& gridAutoColumns() const { return rareNonInheritedData->m_grid->m_gridAutoColumns; }
     const GridTrackSize& gridAutoRows() const { return rareNonInheritedData->m_grid->m_gridAutoRows; }
 
-    const GridPosition& gridItemStart() const { return rareNonInheritedData->m_gridItem->m_gridStart; }
-    const GridPosition& gridItemEnd() const { return rareNonInheritedData->m_gridItem->m_gridEnd; }
-    const GridPosition& gridItemBefore() const { return rareNonInheritedData->m_gridItem->m_gridBefore; }
-    const GridPosition& gridItemAfter() const { return rareNonInheritedData->m_gridItem->m_gridAfter; }
+    const GridPosition& gridStart() const { return rareNonInheritedData->m_gridItem->m_gridStart; }
+    const GridPosition& gridEnd() const { return rareNonInheritedData->m_gridItem->m_gridEnd; }
+    const GridPosition& gridBefore() const { return rareNonInheritedData->m_gridItem->m_gridBefore; }
+    const GridPosition& gridAfter() const { return rareNonInheritedData->m_gridItem->m_gridAfter; }
 
     const ShadowData* boxShadow() const { return rareNonInheritedData->m_boxShadow.get(); }
     void getBoxShadowExtent(LayoutUnit& top, LayoutUnit& right, LayoutUnit& bottom, LayoutUnit& left) const { getShadowExtent(boxShadow(), top, right, bottom, left); }
@@ -1233,10 +1233,11 @@ public:
     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 setGridAutoFlow(GridAutoFlow flow) { SET_VAR(rareNonInheritedData.access()->m_grid, m_gridAutoFlow, flow); }
-    void setGridItemStart(const GridPosition& startPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridStart, startPosition); }
-    void setGridItemEnd(const GridPosition& endPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridEnd, endPosition); }
-    void setGridItemBefore(const GridPosition& beforePosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridBefore, beforePosition); }
-    void setGridItemAfter(const GridPosition& afterPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridAfter, afterPosition); }
+
+    void setGridStart(const GridPosition& startPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridStart, startPosition); }
+    void setGridEnd(const GridPosition& endPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridEnd, endPosition); }
+    void setGridBefore(const GridPosition& beforePosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridBefore, beforePosition); }
+    void setGridAfter(const GridPosition& afterPosition) { SET_VAR(rareNonInheritedData.access()->m_gridItem, m_gridAfter, afterPosition); }
 
     void setMarqueeIncrement(Length f) { SET_VAR(rareNonInheritedData.access()->m_marquee, increment, f); }
     void setMarqueeSpeed(int f) { SET_VAR(rareNonInheritedData.access()->m_marquee, speed, f); }
@@ -1650,7 +1651,10 @@ public:
     static GridTrackSize initialGridAutoRows() { return GridTrackSize(Auto); }
 
     // 'auto' is the default.
-    static GridPosition initialGridPosition() { return GridPosition(); }
+    static GridPosition initialGridStart() { return GridPosition(); }
+    static GridPosition initialGridEnd() { return GridPosition(); }
+    static GridPosition initialGridBefore() { return GridPosition(); }
+    static GridPosition initialGridAfter() { return GridPosition(); }
 
     static unsigned initialTabSize() { return 8; }