Fix 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 bbcf8f535af38fc826047c784e00c1691ea15bf9..0c2025304835c0c4068e6511177a221acc2ec407 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 +852,23 @@ LayoutTable::ColAndColGroup LayoutTable::slowColElementAtAbsoluteColumn(unsigned
     return ColAndColGroup();
 }
 
+unsigned LayoutTable::colElementToAbsoluteColumn(const LayoutTableCol* colElement) const
+{
+    unsigned col = 0;
+
+    for (LayoutTableCol* columnLayoutObject = firstColumn(); columnLayoutObject; columnLayoutObject = columnLayoutObject->nextColumn()) {
+        if (columnLayoutObject == colElement)
+            return col;
+        if (columnLayoutObject->isTableColumnGroupWithColumnChildren()) {
+            // Count spans of leaf col elements only.
+        } else {
+            col += columnLayoutObject->span();
+        }
+    }
+    ASSERT_NOT_REACHED();
+    return 0;
+}
+
 void LayoutTable::recalcSections() const
 {
     ASSERT(m_needsSectionRecalc);