Let collapsed border drawings be cacheable

Source/core/layout/LayoutTableSection.h

Index: Source/core/layout/LayoutTableSection.h
diff --git a/Source/core/layout/LayoutTableSection.h b/Source/core/layout/LayoutTableSection.h
index d47a6587c55506676d0f56cbb104126a06a32a80..e7c53dbae3d944cf5bb4b0309720780078a091cd 100644
--- a/Source/core/layout/LayoutTableSection.h
+++ b/Source/core/layout/LayoutTableSection.h
@@ -210,7 +210,7 @@ public:
     void rowLogicalHeightChanged(LayoutTableRow*);
 
     void removeCachedCollapsedBorders(const LayoutTableCell*);
-    void setCachedCollapsedBorder(const LayoutTableCell*, CollapsedBorderSide, const CollapsedBorderValue&);
+    bool setCachedCollapsedBorder(const LayoutTableCell*, CollapsedBorderSide, const CollapsedBorderValue&);

[pdr., 2015/08/20 07:07:15]

Please add a comment explaining the return value.

// Return true if the collapsed borders change.

[Xianzhu, 2015/08/20 16:39:51]

Done.

     const CollapsedBorderValue& cachedCollapsedBorder(const LayoutTableCell*, CollapsedBorderSide) const;
 
     // distributeExtraLogicalHeightToRows methods return the *consumed* extra logical height.