Fix table cell background 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 bc28e972d5aba743c58880c43cb1d670e0297e5c..14661925fda9b2a1ac837d61827e7569833b8e9d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.h
@@ -313,6 +313,15 @@ public:
     bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect&, unsigned) const override { return false; }
     bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const override { return false; }
 
+    // Returns cell's position before any transformations are applied.
+    LayoutRect getCellPosition(unsigned row, unsigned effectiveColumn) const;

[Xianzhu, 2016/03/28 00:44:42]

Document which coordinate space the returned value is in.

Also don't use 'transformation' whose defined meaning is different from what you
means. 

[atotic1, 2016/03/29 17:05:17]

Done.

+
+    // Returns cell's position after transforms.
+    LayoutRect getCellPhysicalPosition(unsigned row, unsigned effectiveColumn) const;

[Xianzhu, 2016/03/28 00:44:42]

Don't use 'transform'.

[atotic1, 2016/03/29 17:05:16]

Done.

[atotic1, 2016/03/29 17:05:17]

Done.

+
+    // Returns table-relative position of the entire section.
+    LayoutRect positionByCellSpan() const;

[Xianzhu, 2016/03/28 00:44:42]

What does "ByCellSpan" mean?

+
 protected:
     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
@@ -364,6 +373,8 @@ private:
 
     void setLogicalPositionForCell(LayoutTableCell*, unsigned effectiveColumn) const;
 
+    LayoutRect transformLogicalToPhysicalPosition(const LayoutRect& position) const;

[Xianzhu, 2016/03/28 00:44:42]

Don't use 'transform'.

[atotic1, 2016/03/29 17:05:16]

Done.

+
     LayoutObjectChildList m_children;
 
     // The representation of the rows and their cells (CellStruct).