[New Multicolumn] Add support for column-span:all

Source/core/rendering/RenderBlock.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
  * License as published by the Free Software Foundation; either
@@ skipping 1055 matching lines @@
 
         if (child->previousSibling())
             child->previousSibling()->setNextSibling(child->nextSibling());
         if (child->nextSibling())
             child->nextSibling()->setPreviousSibling(child->previousSibling());
     }
 
     child->children()->setFirstChild(0);
     child->m_next = nullptr;
 
-    // Remove all the information in the flow thread associated with the leftover anonymous block.
-    child->removeFromRenderFlowThread();

[Julien - ping for review, 2014/09/30 00:39:32]

Are we sure we don't insert children into the flow-thread that needs to be
cleaned up now?

[mstensho (USE GERRIT), 2014/09/30 20:20:28]

This is an anonymous block, and just became childless. Anonymous blocks don't do
anything special inside a flow thread. The real reason why I had to remove this,
though, is that it calls removeFromRenderFlowThread() while being "half-dead" -
or at least half-detached. This confused flowThreadDescendantWillBeRemoved(),
since that method attempts to walk the subtree.

removeFromRenderFlowThread() is still called from willBeRemovedFromTree(), and
that should be sufficient. It's a pity that removeLeftoverAnonymousBlock() needs
to tear down its child single-handedly, but I'm sure there's a reason for that.
Might as well be related to crbug.com/417556 for all I know. :)

-
     // RenderGrid keeps track of its children, we must notify it about changes in the tree.
     if (child->parent()->isRenderGrid())
         toRenderGrid(child->parent())->dirtyGrid();
 
     child->setParent(0);
     child->setPreviousSibling(0);
     child->setNextSibling(0);
 
     child->destroy();
 }
@@ skipping 429 matching lines @@
         return;
 
     IntRect inflatedRect = pixelSnappedBorderBoxRect();
     RenderTheme::theme().adjustPaintInvalidationRect(this, inflatedRect);
     addVisualOverflow(inflatedRect);
 }
 
 bool RenderBlock::createsBlockFormattingContext() const
 {
     return isInlineBlockOrInlineTable() || isFloatingOrOutOfFlowPositioned() || hasOverflowClip() || isFlexItemIncludingDeprecated()
-        || style()->specifiesColumns() || isRenderFlowThread() || isTableCell() || isTableCaption() || isFieldset() || isWritingModeRoot() || isDocumentElement() || style()->columnSpan();
+        || style()->specifiesColumns() || isRenderFlowThread() || isTableCell() || isTableCaption() || isFieldset() || isWritingModeRoot() || isDocumentElement() || (document().regionBasedColumnsEnabled() ? isColumnSpanAll() : style()->columnSpan());
 }
 
 void RenderBlock::updateBlockChildDirtyBitsBeforeLayout(bool relayoutChildren, RenderBox* child)
 {
     // FIXME: Technically percentage height objects only need a relayout if their percentage isn't going to be turned into
     // an auto value. Add a method to determine this, so that we can avoid the relayout.
     if (relayoutChildren || (child->hasRelativeLogicalHeight() && !isRenderView()))
         child->setChildNeedsLayout(MarkOnlyThis);
 
     // If relayoutChildren is set and the child has percentage padding or an embedded content box, we also need to invalidate the childs pref widths.
@@ skipping 2856 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink