Column balancing support in the region based multicol implementation.

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 2503 matching lines @@
     if (logicalHeightLength.isFillAvailable())
         return containingBlock()->availableLogicalHeight(ExcludeMarginBorderPadding) - borderAndPadding;
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 LayoutUnit RenderBox::computeContentAndScrollbarLogicalHeightUsing(const Length& height, LayoutUnit intrinsicContentHeight) const
 {
     // FIXME(cbiesinger): The css-sizing spec is considering changing what min-content/max-content should resolve to.
     // If that happens, this code will have to change.
-    if (height.isIntrinsic())
+    if (height.isIntrinsic()) {
+        if (intrinsicContentHeight == -1)
+            return -1; // Intrinsic height isn't available.
         return computeIntrinsicLogicalContentHeightUsing(height, intrinsicContentHeight, borderAndPaddingLogicalHeight());
+    }
     if (height.isFixed())
         return height.value();
     if (height.isPercent())
         return computePercentageLogicalHeight(height);
     if (height.isViewportPercentage())
         return valueForLength(height, 0, view());
     return -1;
 }
 
 bool RenderBox::skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock) const
@@ skipping 2026 matching lines @@
 
 void RenderBox::reportStaticMembersMemoryUsage(MemoryInstrumentation* memoryInstrumentation)
 {
     memoryInstrumentation->addRootObject(gOverrideHeightMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideWidthMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideContainingBlockLogicalHeightMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideContainingBlockLogicalWidthMap, WebCoreMemoryTypes::RenderingStructures);
 }
 
 } // namespace WebCore