Add support for the column-fill property.

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index 98b00217d83f95f460a82a2c9c068acf95253ff2..bc4e0e9a5535d503109eab0a95bc272b5290f518 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -801,6 +801,7 @@ public:
     bool hasAutoColumnCount() const { return rareNonInheritedData->m_multiCol->m_autoCount; }
     bool specifiesAutoColumns() const { return hasAutoColumnCount() && hasAutoColumnWidth(); }
     bool specifiesColumns() const { return !hasAutoColumnCount() || !hasAutoColumnWidth() || !hasInlineColumnAxis(); }
+    ColumnFill columnFill() const { return static_cast<ColumnFill>(rareNonInheritedData->m_multiCol->m_fill); }
     float columnGap() const { return rareNonInheritedData->m_multiCol->m_gap; }
     bool hasNormalColumnGap() const { return rareNonInheritedData->m_multiCol->m_normalGap; }
     EBorderStyle columnRuleStyle() const { return rareNonInheritedData->m_multiCol->m_rule.style(); }
@@ -1240,6 +1241,7 @@ public:
     void setHasAutoColumnWidth() { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_autoWidth, true); SET_VAR(rareNonInheritedData.access()->m_multiCol, m_width, 0); }
     void setColumnCount(unsigned short c) { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_autoCount, false); SET_VAR(rareNonInheritedData.access()->m_multiCol, m_count, c); }
     void setHasAutoColumnCount() { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_autoCount, true); SET_VAR(rareNonInheritedData.access()->m_multiCol, m_count, 0); }
+    void setColumnFill(ColumnFill columnFill) { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_fill, columnFill); }
     void setColumnGap(float f) { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_normalGap, false); SET_VAR(rareNonInheritedData.access()->m_multiCol, m_gap, f); }
     void setHasNormalColumnGap() { SET_VAR(rareNonInheritedData.access()->m_multiCol, m_normalGap, true); SET_VAR(rareNonInheritedData.access()->m_multiCol, m_gap, 0); }
     void setColumnRuleColor(const Color& c) { SET_BORDERVALUE_COLOR(rareNonInheritedData.access()->m_multiCol, m_rule, c); }
@@ -1583,6 +1585,7 @@ public:
     static Order initialRTLOrdering() { return LogicalOrder; }
     static float initialTextStrokeWidth() { return 0; }
     static unsigned short initialColumnCount() { return 1; }
+    static ColumnFill initialColumnFill() { return ColumnFillBalance; }
     static ColumnSpan initialColumnSpan() { return ColumnSpanNone; }
     static const TransformOperations& initialTransform() { DEFINE_STATIC_LOCAL(TransformOperations, ops, ()); return ops; }
     static Length initialTransformOriginX() { return Length(50.0, Percent); }