Handle exclusive end offsets when translating from flow thread coordinates.

third_party/WebKit/Source/core/layout/ColumnBalancer.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/ColumnBalancer.h"
 
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 #include "core/layout/LayoutMultiColumnSet.h"
 #include "core/layout/api/LineLayoutBlockFlow.h"
 
@@ skipping 147 matching lines @@
     ASSERT(isFirstAfterBreak(lineTopInFlowThread) || !line.paginationStrut() || !isLogicalTopWithinBounds(lineTopInFlowThread - line.paginationStrut()));
     if (isFirstAfterBreak(lineTopInFlowThread))
         recordStrutBeforeOffset(lineTopInFlowThread, line.paginationStrut());
 }
 
 void InitialColumnHeightFinder::recordStrutBeforeOffset(LayoutUnit offsetInFlowThread, LayoutUnit strut)
 {
     ASSERT(columnSet().usedColumnCount() >= 1);
     unsigned columnCount = columnSet().usedColumnCount();
     ASSERT(m_shortestStruts.size() == columnCount);
-    unsigned index = groupAtOffset(offsetInFlowThread).columnIndexAtOffset(offsetInFlowThread - strut, MultiColumnFragmentainerGroup::AssumeNewColumns);
+    unsigned index = groupAtOffset(offsetInFlowThread).columnIndexAtOffset(offsetInFlowThread - strut, LayoutBox::AssociateWithLatterPage);
     if (index >= columnCount)
         return;
     m_shortestStruts[index] = std::min(m_shortestStruts[index], strut);
 }
 
 LayoutUnit InitialColumnHeightFinder::spaceUsedByStrutsAt(LayoutUnit offsetInFlowThread) const
 {
-    unsigned stopBeforeColumn = groupAtOffset(offsetInFlowThread).columnIndexAtOffset(offsetInFlowThread, MultiColumnFragmentainerGroup::AssumeNewColumns) + 1;
+    unsigned stopBeforeColumn = groupAtOffset(offsetInFlowThread).columnIndexAtOffset(offsetInFlowThread, LayoutBox::AssociateWithLatterPage) + 1;
     stopBeforeColumn = std::min(stopBeforeColumn, columnSet().usedColumnCount());
     ASSERT(stopBeforeColumn <= m_shortestStruts.size());
     LayoutUnit totalStrutSpace;
     for (unsigned i = 0; i < stopBeforeColumn; i++) {
         if (m_shortestStruts[i] != LayoutUnit::max())
             totalStrutSpace += m_shortestStruts[i];
     }
     return totalStrutSpace;
 }
 
@@ skipping 151 matching lines @@
     // of said overflow ends up in the next column. That counts as space shortage.
     const MultiColumnFragmentainerGroup& group = groupAtOffset(lineTopInFlowThread);
     LayoutUnit lineBottomWithOverflow = lineTopInFlowThread + line.lineBottom() - lineTop;
     if (group.columnLogicalTopForOffset(lineTopInFlowThread) != group.columnLogicalTopForOffset(lineBottomWithOverflow)) {
         LayoutUnit shortage = lineBottomWithOverflow - group.columnLogicalTopForOffset(lineBottomWithOverflow);
         recordSpaceShortage(shortage);
     }
 }
 
 } // namespace blink