Introduce LayoutBox::paginationBreakability().

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 582 matching lines @@
     // This looks like a spanner, but if we're inside something unbreakable or something that
     // establishes a new formatting context, it's not to be treated as one.
     for (LayoutBox* ancestor = toLayoutBox(descendant)->parentBox(); ancestor; ancestor = ancestor->containingBlock()) {
         if (ancestor->isLayoutFlowThread()) {
             ASSERT(ancestor == this);
             return true;
         }
         if (!ancestor->isLayoutBlockFlow())
             return false;
         const LayoutBlockFlow& ancestorBlockFlow = *toLayoutBlockFlow(ancestor);
-        if (ancestorBlockFlow.createsNewFormattingContext() || ancestorBlockFlow.isUnsplittableForPagination())
+        if (ancestorBlockFlow.createsNewFormattingContext() || ancestorBlockFlow.paginationBreakability() == ForbidBreaks)
             return false;
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
 void LayoutMultiColumnFlowThread::addColumnSetToThread(LayoutMultiColumnSet* columnSet)
 {
     if (LayoutMultiColumnSet* nextSet = columnSet->nextSiblingMultiColumnSet()) {
         LayoutMultiColumnSetList::iterator it = m_multiColumnSetList.find(nextSet);
@@ skipping 321 matching lines @@
     appendNewFragmentainerGroupIfNeeded(logicalTopInFlowThreadAfterPagination);
 }
 
 void LayoutMultiColumnFlowThread::updateMinimumPageHeight(LayoutUnit offset, LayoutUnit minHeight)
 {
     if (LayoutMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
         multicolSet->updateMinimumColumnHeight(offset, minHeight);
 }
 
 }