Fix Border collapsing with colpsan / rowspan cells

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..4d4f39cd453c637b96a696836187be97b23e31d3 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.h
@@ -341,6 +341,12 @@ class CORE_EXPORT LayoutTableSection final : public LayoutTableBoxComponent {
     return false;
   }
 
+  // Returns cell's position before any transformations are applied.
+  LayoutRect GetCellPosition(unsigned row, unsigned effective_column) const;
+  // Returns cell's position after transforms.
+  LayoutRect GetCellPhysicalPosition(unsigned row,
+                                     unsigned effective_column) const;
+
   int PaginationStrutForRow(LayoutTableRow*, LayoutUnit logical_offset) const;
 
   bool MapToVisualRectInAncestorSpaceInternal(
@@ -357,6 +363,11 @@ class CORE_EXPORT LayoutTableSection final : public LayoutTableBoxComponent {
     return CellSpan(0, Table()->NumEffectiveColumns());
   }
 
+  // Collapsed borders are painted by the section
+  bool PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const override {
+    return false;
+  }
+
  protected:
   void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
   bool NodeAtPoint(HitTestResult&,
@@ -451,7 +462,8 @@ class CORE_EXPORT LayoutTableSection final : public LayoutTableBoxComponent {
   // size accordingly.
   void AdjustRowForPagination(LayoutTableRow&, SubtreeLayoutScope&);
 
-  bool PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const override;
+  LayoutRect TransformLogicalToPhysicalPosition(
+      const LayoutRect& position) const;
 
   // The representation of the rows and their cells (CellStruct).
   Vector<RowStruct> grid_;