Clean up PageBoundaryRule enum.

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 892 matching lines @@
 {
     if (LayoutMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset))
         multicolSet->updateMinimumColumnHeight(offset, minHeight);
 }
 
 bool LayoutMultiColumnFlowThread::addForcedColumnBreak(LayoutUnit offset, LayoutObject* /*breakChild*/, bool /*isBefore*/, LayoutUnit* offsetBreakAdjustment)
 {
     if (LayoutMultiColumnSet* multicolSet = columnSetAtBlockOffset(offset)) {
         multicolSet->addContentRun(offset);
         if (offsetBreakAdjustment)
-            *offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, IncludePageBoundary) : LayoutUnit();
+            *offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, AssociateWithFormerPage) : LayoutUnit();
         return true;
     }
     return false;
 }
 
 bool LayoutMultiColumnFlowThread::isPageLogicalHeightKnown() const
 {
     if (LayoutMultiColumnSet* columnSet = lastMultiColumnSet())
         return columnSet->isPageLogicalHeightKnown();
     return false;
 }
 
 }