Correctly account for nested multicol top border / padding.

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 368 matching lines @@
 
 void LayoutMultiColumnFlowThread::layoutColumns(SubtreeLayoutScope& layoutScope)
 {
     // Since we ended up here, it means that the multicol container (our parent) needed
     // layout. Since contents of the multicol container are diverted to the flow thread, the flow
     // thread needs layout as well.
     layoutScope.setChildNeedsLayout(this);
 
     if (FragmentationContext* enclosingFragmentationContext = this->enclosingFragmentationContext()) {
         m_blockOffsetInEnclosingFragmentationContext = multiColumnBlockFlow()->offsetFromLogicalTopOfFirstPage();
+        m_blockOffsetInEnclosingFragmentationContext += multiColumnBlockFlow()->borderAndPaddingBefore();
 
         if (LayoutMultiColumnFlowThread* enclosingFlowThread = enclosingFragmentationContext->associatedFlowThread()) {
             if (LayoutMultiColumnSet* firstSet = firstMultiColumnSet()) {
                 // Before we can start to lay out the contents of this multicol container, we need
                 // to make sure that all ancestor multicol containers have established a row to hold
                 // the first column contents of this container (this multicol container may start at
                 // the beginning of a new outer row). Without sufficient rows in all ancestor
                 // multicol containers, we may use the wrong column height.
                 LayoutUnit offset = m_blockOffsetInEnclosingFragmentationContext + firstSet->logicalTopFromMulticolContentEdge();
                 enclosingFlowThread->appendNewFragmentainerGroupIfNeeded(offset, AssociateWithLatterPage);
@@ skipping 592 matching lines @@
         }
         if (canContainSpannerInParentFragmentationContext(*object))
             next = object->nextInPreOrder(&root);
         else
             next = object->nextInPreOrderAfterChildren(&root);
     }
     return true;
 }
 
 } // namespace blink