Introduce maxColumnLogicalHeight() and clean up a little.

third_party/WebKit/Source/core/layout/LayoutMultiColumnFlowThread.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 257 matching lines @@
     multicolContainer->resetMultiColumnFlowThread();
     moveAllChildrenTo(multicolContainer, true);
 
     // We used to manually nuke the line box tree here, but that should happen automatically when
     // moving children around (the code above).
     ASSERT(!firstLineBox());
 
     destroy();
 }
 
+LayoutUnit LayoutMultiColumnFlowThread::maxColumnLogicalHeight() const
+{
+    if (m_columnHeightAvailable) {
+        // If height is non-auto, it's already constrained against max-height as well.
+        // Just return it.
+        return m_columnHeightAvailable;
+    }
+    const LayoutBlockFlow* multicolBlock = multiColumnBlockFlow();
+    Length logicalMaxHeight = multicolBlock->style()->logicalMaxHeight();
+    if (!logicalMaxHeight.isMaxSizeNone()) {
+        LayoutUnit resolvedLogicalMaxHeight = multicolBlock->computeContentLogicalHeight(MaxSize, logicalMaxHeight, -1);
+        if (resolvedLogicalMaxHeight != -1)
+            return resolvedLogicalMaxHeight;
+    }
+    return LayoutUnit::max();
+}
+
 LayoutUnit LayoutMultiColumnFlowThread::tallestUnbreakableLogicalHeight(LayoutUnit offsetInFlowThread) const
 {
     if (LayoutMultiColumnSet* multicolSet = columnSetAtBlockOffset(offsetInFlowThread))
         return multicolSet->tallestUnbreakableLogicalHeight();
     return LayoutUnit();
 }
 
 LayoutSize LayoutMultiColumnFlowThread::columnOffset(const LayoutPoint& point) const
 {
     if (!hasValidColumnSetInfo())
@@ skipping 670 matching lines @@
         }
         if (canContainSpannerInParentFragmentationContext(*object))
             next = object->nextInPreOrder(&root);
         else
             next = object->nextInPreOrderAfterChildren(&root);
     }
     return true;
 }
 
 } // namespace blink