[New Multicolumn] Preparatory work for nested multicol support.

Source/core/rendering/RenderMultiColumnFlowThread.cpp

Index: Source/core/rendering/RenderMultiColumnFlowThread.cpp
diff --git a/Source/core/rendering/RenderMultiColumnFlowThread.cpp b/Source/core/rendering/RenderMultiColumnFlowThread.cpp
index 5657d2ccf9594d7215d6e1004104400cd92b61cc..85470326dfb72e89b6f731d7d240fc18d2b6dd49 100644
--- a/Source/core/rendering/RenderMultiColumnFlowThread.cpp
+++ b/Source/core/rendering/RenderMultiColumnFlowThread.cpp
@@ -276,7 +276,7 @@ bool RenderMultiColumnFlowThread::recalculateColumnHeights()
     // columns, unless we have a bug.
     bool needsRelayout = false;
     for (RenderMultiColumnSet* multicolSet = firstMultiColumnSet(); multicolSet; multicolSet = multicolSet->nextSiblingMultiColumnSet()) {
-        needsRelayout |= multicolSet->recalculateColumnHeight(m_inBalancingPass ? RenderMultiColumnSet::StretchBySpaceShortage : RenderMultiColumnSet::GuessFromFlowThreadPortion);
+        needsRelayout |= multicolSet->recalculateColumnHeight(m_inBalancingPass ? StretchBySpaceShortage : GuessFromFlowThreadPortion);
         if (needsRelayout) {
             // Once a column set gets a new column height, that column set and all successive column
             // sets need to be laid out over again, since their logical top will be affected by
@@ -647,13 +647,13 @@ void RenderMultiColumnFlowThread::setPageBreak(LayoutUnit offset, LayoutUnit spa
         return;
 
     if (RenderMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
-        multicolSet->recordSpaceShortage(spaceShortage);
+        multicolSet->recordSpaceShortage(offset, spaceShortage);
 }
 
 void RenderMultiColumnFlowThread::updateMinimumPageHeight(LayoutUnit offset, LayoutUnit minHeight)
 {
     if (RenderMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
-        multicolSet->updateMinimumColumnHeight(minHeight);
+        multicolSet->updateMinimumColumnHeight(offset, minHeight);
 }
 
 bool RenderMultiColumnFlowThread::addForcedRegionBreak(LayoutUnit offset, RenderObject* /*breakChild*/, bool /*isBefore*/, LayoutUnit* offsetBreakAdjustment)