Optimize collapsed border calculation (step 2)

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

Index: third_party/WebKit/Source/core/layout/LayoutTableSection.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableSection.h b/third_party/WebKit/Source/core/layout/LayoutTableSection.h
index 9c80602b16980922f0b18ff20f0309d5b4d56e01..56c55ad91ee0a6a22771d0262dd4edf5a83fdd9e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.h
@@ -357,6 +357,15 @@ class CORE_EXPORT LayoutTableSection final : public LayoutTableBoxComponent {
     return CellSpan(0, Table()->NumEffectiveColumns());
   }
 
+  // Return the primary cell of the table grid slot above or below grid slot
+  // (row, effectiveColumn).
+  LayoutTableCell* PrimaryCellAboveInTable(unsigned row,
+                                           unsigned effective_column);
+  LayoutTableCell* PrimaryCellBelowInTable(unsigned row,
+                                           unsigned effective_column);
+
+  void InvalidateCellCollapsedBordersIntersectingRow(unsigned row_index);
+
  protected:
   void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
   bool NodeAtPoint(HitTestResult&,
@@ -453,6 +462,8 @@ class CORE_EXPORT LayoutTableSection final : public LayoutTableBoxComponent {
 
   bool PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const override;
 
+  void InvalidateCollapsedBordersOfAffectedCells();

[wkorman, 2017/04/27 22:05:36]

Same as previous comment re: "OfAffectedCells"

+
   // The representation of the rows and their cells (CellStruct).
   Vector<RowStruct> grid_;