Recalculate column heights as part of column set layout.

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

 /*
  * Copyright (C) 2012 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 275 matching lines @@
 
 void LayoutMultiColumnSet::endFlow(LayoutUnit offsetInFlowThread)
 {
     // At this point layout is exactly at the end of this set. Store block offset from flow thread
     // start. This set is now considered "flowed", although we may have to revisit it later (with
     // beginFlow()), e.g. if a subtree in the flow thread has to be laid out over again because the
     // initial margin collapsing estimates were wrong.
     m_fragmentainerGroups.last().setLogicalBottomInFlowThread(offsetInFlowThread);
 }
 
+void LayoutMultiColumnSet::layout()
+{
+    if (recalculateColumnHeight())
+        multiColumnFlowThread()->setColumnHeightsChanged();
+    LayoutBlockFlow::layout();
+}
+
 void LayoutMultiColumnSet::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
 {
     minLogicalWidth = m_flowThread->minPreferredLogicalWidth();
     maxLogicalWidth = m_flowThread->maxPreferredLogicalWidth();
 }
 
 void LayoutMultiColumnSet::computeLogicalHeight(LayoutUnit, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
 {
     LayoutUnit logicalHeight;
     for (const auto& group : m_fragmentainerGroups)
@@ skipping 91 matching lines @@
 
 LayoutRect LayoutMultiColumnSet::flowThreadPortionRect() const
 {
     LayoutRect portionRect(LayoutUnit(), logicalTopInFlowThread(), pageLogicalWidth(), logicalHeightInFlowThread());
     if (!isHorizontalWritingMode())
         return portionRect.transposedRect();
     return portionRect;
 }
 
 }