Remove legacy markup box behavior when line-clamping.

Source/core/paint/EllipsisBoxPainter.h

 // Copyright 2014 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.
 
 #ifndef EllipsisBoxPainter_h
 #define EllipsisBoxPainter_h
 
 namespace blink {
 
 struct PaintInfo;
 
 class EllipsisBox;
 class FloatPoint;
 class Font;
 class GraphicsContext;
 class LayoutPoint;
 class LayoutUnit;
 class ComputedStyle;
 
 class EllipsisBoxPainter {
 public:
     EllipsisBoxPainter(EllipsisBox& ellipsisBox) : m_ellipsisBox(ellipsisBox) { }
 
     void paint(const PaintInfo&, const LayoutPoint&, LayoutUnit lineTop, LayoutUnit lineBottom);
 
 private:
     void paintEllipsis(const PaintInfo&, const LayoutPoint& paintOffset, LayoutUnit lineTop, LayoutUnit lineBottom, const ComputedStyle&);
-    void paintMarkupBox(const PaintInfo&, const LayoutPoint& paintOffset, LayoutUnit lineTop, LayoutUnit lineBottom, const ComputedStyle&);
     void paintSelection(GraphicsContext*, const FloatPoint&, const ComputedStyle&, const Font&);
 
     EllipsisBox& m_ellipsisBox;
 };
 
 } // namespace blink
 
 #endif // EllipsisBoxPainter_h