A column-span:all element should always establish a new formatting context.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. 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 541 matching lines @@
   LayoutTheme::theme().addVisualOverflow(*this, inflatedRect);
   addSelfVisualOverflow(LayoutRect(inflatedRect));
 }
 
 DISABLE_CFI_PERF
 bool LayoutBlock::createsNewFormattingContext() const {
   return isInlineBlockOrInlineTable() || isFloatingOrOutOfFlowPositioned() ||
          hasOverflowClip() || isFlexItemIncludingDeprecated() ||
          style()->specifiesColumns() || isLayoutFlowThread() || isTableCell() ||
          isTableCaption() || isFieldset() || isWritingModeRoot() ||
-         isDocumentElement() || isColumnSpanAll() || isGridItem() ||
+         isDocumentElement() || isGridItem() ||
+         style()->getColumnSpan() == ColumnSpanAll ||
          style()->containsPaint() || style()->containsLayout() ||
          isSVGForeignObject() || style()->display() == EDisplay::kFlowRoot;
 }
 
 static inline bool changeInAvailableLogicalHeightAffectsChild(
     LayoutBlock* parent,
     LayoutBox& child) {
   if (parent->style()->boxSizing() != EBoxSizing::kBorderBox)
     return false;
   return parent->style()->isHorizontalWritingMode() &&
@@ skipping 1604 matching lines @@
   }
 
   return availableHeight;
 }
 
 bool LayoutBlock::hasDefiniteLogicalHeight() const {
   return availableLogicalHeightForPercentageComputation() != LayoutUnit(-1);
 }
 
 }  // namespace blink