Table cell background painting

third_party/WebKit/Source/core/layout/LayoutTable.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTable.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTable.cpp b/third_party/WebKit/Source/core/layout/LayoutTable.cpp
index c25bb9d453251f636249256fd426f2f68264bab7..f22824692ff6612a64168d1f5c787a9f124e3a78 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTable.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTable.cpp
@@ -734,6 +734,14 @@ LayoutTableSection* LayoutTable::topNonEmptySection() const
     return section;
 }
 
+LayoutTableSection* LayoutTable::bottomNonEmptySection() const
+{
+    LayoutTableSection* section = bottomSection();
+    if (section && !section->numRows())
+        section = sectionAbove(section, SkipEmptySections);
+    return section;
+}
+
 void LayoutTable::splitEffectiveColumn(unsigned index, unsigned firstSpan)
 {
     // We split the column at |index|, taking |firstSpan| cells from the span.
@@ -844,6 +852,25 @@ LayoutTable::ColAndColGroup LayoutTable::slowColElementAtAbsoluteColumn(unsigned
     return ColAndColGroup();
 }
 
+// Inverse of slowColElement:

[Xianzhu, 2016/03/09 18:40:55]

There is no more slowColElement. It's renamed to
slowColElementAtAbsoluteColumn(). Please update.

[atotic1, 2016/03/15 16:50:48]

Done.

+// maps LayoutTableCol to effectiveColumnIndex useful for columnPositions

[Xianzhu, 2016/03/09 18:40:55]

Start a sentence with an uppercase letter.
Add a ';' or '.' at the end.

[atotic1, 2016/03/15 16:50:48]

Done.

+// returns npos if out of range

[Xianzhu, 2016/03/09 18:40:55]

Add a '.' at the end.
We should always find the column of the element (should ASSERT the situation of
not-found), so we should never return error result. 

[atotic1, 2016/03/15 16:50:48]

You are correct. I was finding absolute columns, not effective. Fixe.

+unsigned LayoutTable::colElementToEffectiveColumn(const LayoutTableCol * colElement) const
+{
+    unsigned col = 0;
+    unsigned i;
+    for (i = 0; i < m_columnLayoutObjects.size(); i++) {
+        if (colElement == m_columnLayoutObjects[i]) {
+            break;
+        }
+        col += m_columnLayoutObjects[i]->span();

[Xianzhu, 2016/03/09 18:40:55]

m_columnLayoutObjects[i].span is in number of absolute columns. If you sum up it
here, you'll get the index of absolute column, not effective column.

[atotic1, 2016/03/15 16:50:48]

Done.

+    }
+    if (col < numEffectiveColumns())
+        return col;
+    // else
+        return npos;
+}
+
 void LayoutTable::recalcSections() const
 {
     ASSERT(m_needsSectionRecalc);