Update outer flow thread membership before changing multicolness.

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 819 matching lines @@
     // If an in-flow descendant goes out-of-flow, we may have to remove column sets and spanner placeholders.
     return (newStyle.hasOutOfFlowPosition() && !oldStyle.hasOutOfFlowPosition()) || needsToReinsertIntoFlowThread(oldStyle, newStyle);
 }
 
 static inline bool needsToInsertIntoFlowThread(const ComputedStyle& oldStyle, const ComputedStyle& newStyle)
 {
     // If an out-of-flow descendant goes in-flow, we may have to insert column sets and spanner placeholders.
     return (!newStyle.hasOutOfFlowPosition() && oldStyle.hasOutOfFlowPosition()) || needsToReinsertIntoFlowThread(oldStyle, newStyle);
 }
 
-void LayoutMultiColumnFlowThread::flowThreadDescendantStyleWillChange(LayoutObject* descendant, StyleDifference diff, const ComputedStyle& newStyle)
+void LayoutMultiColumnFlowThread::flowThreadDescendantStyleWillChange(LayoutBox* descendant, StyleDifference diff, const ComputedStyle& newStyle)
 {
-    if (descendant->isText()) {
-        // Text nodes inherit all properties from the parent node (including non-inheritable
-        // ones). We don't care what its 'position' is. In fact, we _must_ ignore it, since the
-        // parent may be the multicol container, and having that accidentally leaked into children
-        // of the multicol is bad.
-        return;
-    }
     if (needsToRemoveFromFlowThread(descendant->styleRef(), newStyle))
         flowThreadDescendantWillBeRemoved(descendant);
 }
 
-void LayoutMultiColumnFlowThread::flowThreadDescendantStyleDidChange(LayoutObject* descendant, StyleDifference diff, const ComputedStyle& oldStyle)
+void LayoutMultiColumnFlowThread::flowThreadDescendantStyleDidChange(LayoutBox* descendant, StyleDifference diff, const ComputedStyle& oldStyle)
 {
-    if (descendant->isText()) {
-        // Text nodes inherit all properties from the parent node (including non-inheritable
-        // ones). We don't care what its 'position' is. In fact, we _must_ ignore it, since the
-        // parent may be the multicol container, and having that accidentally leaked into children
-        // of the multicol is bad.
-        return;
-    }
     if (needsToInsertIntoFlowThread(oldStyle, descendant->styleRef())) {
         flowThreadDescendantWasInserted(descendant);
         return;
     }
     if (descendantIsValidColumnSpanner(descendant)) {
         // We went from being regular column content to becoming a spanner.
-        ASSERT(!toLayoutBox(descendant)->spannerPlaceholder());
+        ASSERT(!descendant->spannerPlaceholder());
 
         // First remove this as regular column content. Note that this will walk the entire subtree
         // of |descendant|. There might be spanners there (which won't be spanners anymore, since
         // we're not allowed to nest spanners), whose placeholders must die.
         flowThreadDescendantWillBeRemoved(descendant);
 
-        createAndInsertSpannerPlaceholder(toLayoutBox(descendant), nextInPreOrderAfterChildrenSkippingOutOfFlow(this, descendant));
+        createAndInsertSpannerPlaceholder(descendant, nextInPreOrderAfterChildrenSkippingOutOfFlow(this, descendant));
     }
 }
 
 void LayoutMultiColumnFlowThread::computePreferredLogicalWidths()
 {
     LayoutFlowThread::computePreferredLogicalWidths();
 
     // The min/max intrinsic widths calculated really tell how much space elements need when
     // laid out inside the columns. In order to eventually end up with the desired column width,
     // we need to convert them to values pertaining to the multicol container.
@@ skipping 79 matching lines @@
     if (LayoutMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset)) {
         multicolSet->addContentRun(offset);
         if (offsetBreakAdjustment)
             *offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, AssociateWithFormerPage) : LayoutUnit();
         return true;
     }
     return false;
 }
 
 }