Fix Border collapsing with colpsan / rowspan cells

third_party/WebKit/Source/core/paint/TablePainter.cpp

Index: third_party/WebKit/Source/core/paint/TablePainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/TablePainter.cpp b/third_party/WebKit/Source/core/paint/TablePainter.cpp
index 4c8960d476ab995648cc1d9bf9b4862848d0fd9d..e4a18ec07a1283349f9cb19178b21bbb3f214a0b 100644
--- a/third_party/WebKit/Source/core/paint/TablePainter.cpp
+++ b/third_party/WebKit/Source/core/paint/TablePainter.cpp
@@ -6,13 +6,14 @@
 
 #include "core/layout/LayoutTable.h"
 #include "core/layout/LayoutTableSection.h"
-#include "core/style/CollapsedBorderValue.h"
 #include "core/paint/BoxClipper.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/ObjectPainter.h"
 #include "core/paint/PaintInfo.h"
+#include "core/paint/TableCollapsedBorderPainter.h"
 #include "core/paint/TableSectionPainter.h"
+#include "core/style/CollapsedBorderValue.h"
 
 namespace blink {
 
@@ -47,20 +48,13 @@ void TablePainter::PaintObject(const PaintInfo& paint_info,
     if (layout_table_.CollapseBorders() &&
         ShouldPaintDescendantBlockBackgrounds(paint_phase) &&
         layout_table_.Style()->Visibility() == EVisibility::kVisible) {
-      // Using our cached sorted styles, we then do individual passes,
-      // painting each style of border from lowest precedence to highest
-      // precedence.
-      LayoutTable::CollapsedBorderValues collapsed_borders =
-          layout_table_.CollapsedBorders();
-      size_t count = collapsed_borders.size();
-      for (size_t i = 0; i < count; ++i) {
-        for (LayoutTableSection* section = layout_table_.BottomSection();
-             section; section = layout_table_.SectionAbove(section)) {
-          LayoutPoint child_point =
-              layout_table_.FlipForWritingModeForChild(section, paint_offset);
-          TableSectionPainter(*section).PaintCollapsedBorders(
-              paint_info_for_descendants, child_point, collapsed_borders[i]);
-        }
+      TableCollapsedBorderPainter old_painter(layout_table_.BottomSection());
+      for (LayoutTableSection* section = layout_table_.BottomSection(); section;
+           section = layout_table_.SectionAbove(section, kSkipEmptySections)) {
+        LayoutPoint child_point =
+            layout_table_.FlipForWritingModeForChild(section, paint_offset);
+        TableSectionPainter(*section).PaintCollapsedBorders(
+            paint_info_for_descendants, child_point, old_painter);
       }
     }
   }