[New Multicolumn] Remove RenderRegionSet.

Source/core/rendering/RenderMultiColumnSet.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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 
 #ifndef RenderMultiColumnSet_h
 #define RenderMultiColumnSet_h
 
 #include "core/rendering/RenderMultiColumnFlowThread.h"
-#include "core/rendering/RenderRegionSet.h"
+#include "core/rendering/RenderRegion.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 // RenderMultiColumnSet represents a set of columns that all have the same width and height. By
 // combining runs of same-size columns into a single object, we significantly reduce the number of
 // unique RenderObjects required to represent columns.
 //
 // Column sets are inserted as anonymous children of the actual multicol container (i.e. the
 // renderer whose style computes to non-auto column-count and/or column-width).
 //
 // Being a "region", a column set has no children on its own, but is merely used to slice a portion
 // of the tall "single-column" flow thread into actual columns visually, to convert from flow thread
 // coordinates to visual ones. It is in charge of both positioning columns correctly relatively to
 // the parent multicol container, and to calculate the correct translation for each column's
 // contents, and to paint any rules between them. RenderMultiColumnSet objects are used for
 // painting, hit testing, and any other type of operation that requires mapping from flow thread
 // coordinates to visual coordinates.
 //
 // Column spans result in the creation of new column sets, since a spanning renderer has to be
 // placed in between the column sets that come before and after the span.
-class RenderMultiColumnSet FINAL : public RenderRegionSet {
+class RenderMultiColumnSet FINAL : public RenderRegion {
 public:
     static RenderMultiColumnSet* createAnonymous(RenderFlowThread*, RenderStyle* parentStyle);
 
     virtual bool isRenderMultiColumnSet() const OVERRIDE { return true; }
 
     RenderBlockFlow* multiColumnBlockFlow() const { return toRenderBlockFlow(parent()); }
     RenderMultiColumnFlowThread* multiColumnFlowThread() const
     {
         ASSERT_WITH_SECURITY_IMPLICATION(!flowThread() || flowThread()->isRenderMultiColumnFlowThread());
         return static_cast<RenderMultiColumnFlowThread*>(flowThread());
@@ skipping 32 matching lines @@
     // Record space shortage (the amount of space that would have been enough to prevent some
     // element from being moved to the next column) at a column break. The smallest amount of space
     // shortage we find is the amount with which we will stretch the column height, if it turns out
     // after layout that the columns weren't tall enough.
     void recordSpaceShortage(LayoutUnit spaceShortage);
 
     virtual void updateLogicalWidth() OVERRIDE;
 
     void prepareForLayout();
 
+    // Expand this set's flow thread portion rectangle to contain all trailing flow thread
+    // overflow. Only to be called on the last set.
+    void expandToEncompassFlowThreadContentsIfNeeded();
+
 private:
     RenderMultiColumnSet(RenderFlowThread*);
 
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const OVERRIDE;
 
     virtual void paintObject(PaintInfo&, const LayoutPoint& paintOffset) OVERRIDE;
 
     virtual LayoutUnit pageLogicalWidth() const OVERRIDE { return m_computedColumnWidth; }
     virtual LayoutUnit pageLogicalHeight() const OVERRIDE { return m_computedColumnHeight; }
 
@@ skipping 72 matching lines @@
     };
     Vector<ContentRun, 1> m_contentRuns;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderMultiColumnSet, isRenderMultiColumnSet());
 
 } // namespace WebCore
 
 #endif // RenderMultiColumnSet_h