Optimize collapsed border painting

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 7dacf875541bb7b7e9d7a2c08a458c2243b2049b..6cb88b631637b6c7ba013a25370859efcc1f49ac 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.h
@@ -34,13 +34,6 @@ namespace blink {
 // This variable is used to balance the memory consumption vs the paint invalidation time on big tables.
 const float gMaxAllowedOverflowingCellRatioForFastPaintPath = 0.1f;
 
-enum CollapsedBorderSide {
-    CBSBefore,
-    CBSAfter,
-    CBSStart,
-    CBSEnd
-};
-
 // Helper class for paintObject.
 class CellSpan {
     STACK_ALLOCATED();
@@ -278,11 +271,6 @@ public:
 
     void rowLogicalHeightChanged(LayoutTableRow*);
 
-    void removeCachedCollapsedBorders(const LayoutTableCell*);
-    // Returns true if any collapsed borders of the cell changed.
-    bool setCachedCollapsedBorder(const LayoutTableCell*, CollapsedBorderSide, const CollapsedBorderValue&);
-    const CollapsedBorderValue& cachedCollapsedBorder(const LayoutTableCell*, CollapsedBorderSide) const;
-
     // distributeExtraLogicalHeightToRows methods return the *consumed* extra logical height.
     // FIXME: We may want to introduce a structure holding the in-flux layout information.
     int distributeExtraLogicalHeightToRows(int extraLogicalHeight);
@@ -403,11 +391,6 @@ private:
     // The use is to disable a painting optimization where we just paint the
     // invalidated cells.
     bool m_hasMultipleCellLevels;
-
-    // This map holds the collapsed border values for cells with collapsed borders.
-    // It is held at LayoutTableSection level to spare memory consumption by table cells.
-    using CellsCollapsedBordersMap = HashMap<std::pair<const LayoutTableCell*, int>, CollapsedBorderValue>;
-    CellsCollapsedBordersMap m_cellsCollapsedBorders;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTableSection, isTableSection());