Cleanup: Remove LayoutRegion.

Source/core/layout/LayoutMultiColumnFlowThread.h

 /*
  * 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 26 matching lines @@
 
 enum BalancedColumnHeightCalculation { GuessFromFlowThreadPortion, StretchBySpaceShortage };
 
 // Flow thread implementation for CSS multicol. This will be inserted as an anonymous child block of
 // the actual multicol container (i.e. the LayoutBlockFlow whose style computes to non-auto
 // column-count and/or column-width). LayoutMultiColumnFlowThread is the heart of the multicol
 // implementation, and there is only one instance per multicol container. Child content of the
 // multicol container is parented into the flow thread at the time of layoutObject insertion.
 //
 // Apart from this flow thread child, the multicol container will also have LayoutMultiColumnSet
-// "region" children, which are used to position the columns visually. The flow thread is in charge
+// children, which are used to position the columns visually. The flow thread is in charge
 // of layout, and, after having calculated the column width, it lays out content as if everything
 // were in one tall single column, except that there will typically be some amount of blank space
 // (also known as pagination struts) at the offsets where the actual column boundaries are. This
 // way, content that needs to be preceded by a break will appear at the top of the next
 // column. Content needs to be preceded by a break when there's a forced break or when the content
 // is unbreakable and cannot fully fit in the same column as the preceding piece of
 // content. Although a LayoutMultiColumnFlowThread is laid out, it does not take up any space in its
 // container. It's the LayoutMultiColumnSet objects that take up the necessary amount of space, and
 // make sure that the columns are painted and hit-tested correctly.
 //
@@ skipping 127 matching lines @@
     void setProgressionIsInline(bool isInline) { m_progressionIsInline = isInline; }
 
     virtual void layout() override;
 
 private:
     void calculateColumnCountAndWidth(LayoutUnit& width, unsigned& count) const;
     void createAndInsertMultiColumnSet(LayoutBox* insertBefore = 0);
     void createAndInsertSpannerPlaceholder(LayoutBox* spanner, LayoutBox* insertBefore = 0);
     virtual bool descendantIsValidColumnSpanner(LayoutObject* descendant) const;
 
-    virtual void addRegionToThread(LayoutMultiColumnSet*) override;
+    virtual void addColumnSetToThread(LayoutMultiColumnSet*) override;
     virtual void willBeRemovedFromTree() override;
     virtual LayoutUnit skipColumnSpanner(LayoutBox*, LayoutUnit logicalTopInFlowThread) override;
     virtual void flowThreadDescendantWasInserted(LayoutObject*) override;
     virtual void flowThreadDescendantWillBeRemoved(LayoutObject*) override;
     virtual void computePreferredLogicalWidths() override;
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
     virtual void updateLogicalWidth() override;
     virtual void setPageBreak(LayoutUnit offset, LayoutUnit spaceShortage) override;
     virtual void updateMinimumPageHeight(LayoutUnit offset, LayoutUnit minHeight) override;
-    virtual bool addForcedRegionBreak(LayoutUnit, LayoutObject* breakChild, bool isBefore, LayoutUnit* offsetBreakAdjustment = 0) override;
+    virtual bool addForcedColumnBreak(LayoutUnit, LayoutObject* breakChild, bool isBefore, LayoutUnit* offsetBreakAdjustment = 0) override;
     virtual bool isPageLogicalHeightKnown() const override;
 
     // The last set we worked on. It's not to be used as the "current set". The concept of a
     // "current set" is difficult, since layout may jump back and forth in the tree, due to wrong
     // top location estimates (due to e.g. margin collapsing), and possibly for other reasons.
     LayoutMultiColumnSet* m_lastSetWorkedOn;
 
     unsigned m_columnCount; // The used value of column-count
     LayoutUnit m_columnHeightAvailable; // Total height available to columns, or 0 if auto.
     bool m_inBalancingPass; // Set when relayouting for column balancing.
     bool m_needsColumnHeightsRecalculation; // Set when we need to recalculate the column set heights after layout.
     bool m_progressionIsInline; // Always true for regular multicol. False for paged-y overflow.
     bool m_isBeingEvacuated;
 };
 
 } // namespace blink
 
 #endif // LayoutMultiColumnFlowThread_h