1 files changed, 13 insertions, 7 deletions

diff --git a/Source/WebCore/rendering/RenderMultiColumnBlock.h b/Source/WebCore/rendering/RenderMultiColumnBlock.h
index 58850c334..f4408ae98 100644
--- a/Source/WebCore/rendering/RenderMultiColumnBlock.h
+++ b/Source/WebCore/rendering/RenderMultiColumnBlock.h
@@ -35,21 +35,26 @@ class RenderMultiColumnFlowThread;
 
 class RenderMultiColumnBlock : public RenderBlock {
 public:
-    RenderMultiColumnBlock(Node*);
-    
-    LayoutUnit columnHeight() const { return m_columnHeight; }
-    void setColumnHeight(LayoutUnit columnHeight) { m_columnHeight = columnHeight; }
+    RenderMultiColumnBlock(Element*);
+
+    LayoutUnit columnHeightAvailable() const { return m_columnHeightAvailable; }
 
     LayoutUnit columnWidth() const { return m_columnWidth; }
     unsigned columnCount() const { return m_columnCount; }
 
     RenderMultiColumnFlowThread* flowThread() const { return m_flowThread; }
 
+    bool requiresBalancing() const { return !m_columnHeightAvailable; }
+
 private:
     virtual bool isRenderMultiColumnBlock() const { return true; }
     
     virtual const char* renderName() const;
 
+    virtual RenderObject* layoutSpecialExcludedChild(bool relayoutChildren) OVERRIDE;
+
+    virtual void styleDidChange(StyleDifference, const RenderStyle*) OVERRIDE;
+    
     virtual bool updateLogicalWidthAndColumnWidth() OVERRIDE;
     virtual void checkForPaginationLogicalHeightChange(LayoutUnit& pageLogicalHeight, bool& pageLogicalHeightChanged, bool& hasSpecifiedPageLogicalHeight) OVERRIDE;
     virtual bool relayoutForPagination(bool hasSpecifiedPageLogicalHeight, LayoutUnit pageLogicalHeight, LayoutStateMaintainer&) OVERRIDE;
@@ -64,18 +69,19 @@ private:
     unsigned m_columnCount;   // The default column count/width that are based off our containing block width. These values represent only the default,
     LayoutUnit m_columnWidth; // since a multi-column block that is split across variable width pages or regions will have different column counts and widths in each.
                               // These values will be cached (eventually) for multi-column blocks.
-    LayoutUnit m_columnHeight; // The current column height.
+    LayoutUnit m_columnHeightAvailable; // Total height available to columns, or 0 if auto.
+    bool m_inBalancingPass; // Set when relayouting for column balancing.
 };
 
 inline RenderMultiColumnBlock* toRenderMultiColumnBlock(RenderObject* object)
 {
-    ASSERT(!object || object->isRenderMultiColumnBlock());
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderMultiColumnBlock());
     return static_cast<RenderMultiColumnBlock*>(object);
 }
 
 inline const RenderMultiColumnBlock* toRenderMultiColumnBlock(const RenderObject* object)
 {
-    ASSERT(!object || object->isRenderMultiColumnBlock());
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderMultiColumnBlock());
     return static_cast<const RenderMultiColumnBlock*>(object);
 }