Clear descendant floats when moving children of a multicol container to a flowthread

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 227 matching lines @@
     return nullptr;
 }
 
 void LayoutMultiColumnFlowThread::populate()
 {
     LayoutBlockFlow* multicolContainer = multiColumnBlockFlow();
     ASSERT(!nextSibling());
     // Reparent children preceding the flow thread into the flow thread. It's multicol content
     // now. At this point there's obviously nothing after the flow thread, but layoutObjects (column
     // sets and spanners) will be inserted there as we insert elements into the flow thread.
+    multicolContainer->removeFloatingObjectsFromDescendants();
     multicolContainer->moveChildrenTo(this, multicolContainer->firstChild(), this, true);
 }
 
 void LayoutMultiColumnFlowThread::evacuateAndDestroy()
 {
     LayoutBlockFlow* multicolContainer = multiColumnBlockFlow();
     m_isBeingEvacuated = true;
 
     // Remove all sets and spanners.
     while (LayoutBox* columnBox = firstMultiColumnBox()) {
@@ skipping 717 matching lines @@
         }
         if (canContainSpannerInParentFragmentationContext(*object))
             next = object->nextInPreOrder(&root);
         else
             next = object->nextInPreOrderAfterChildren(&root);
     }
     return true;
 }
 
 } // namespace blink