Remove GlyphOverflow.computeBounds as it's no longer used for -webkit-line-box-contain.

Source/core/layout/line/GlyphOverflow.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef GlyphOverflow_h
 #define GlyphOverflow_h
 
 #include "platform/geometry/FloatRect.h"
 #include "wtf/Allocator.h"
-#include <math.h>
+#include <algorithm>
 
 namespace blink {
 
 struct GlyphOverflow {
     STACK_ALLOCATED();
     GlyphOverflow()
         : left(0)
         , right(0)
         , top(0)
         , bottom(0)
-        , computeBounds(false)
     {
     }
 
     bool isZero() const
     {
         return !left && !right && !top && !bottom;
     }
 
     void setFromBounds(const FloatRect& bounds, float ascent, float descent, float textWidth)
     {
-        top = ceilf(computeBounds ? -bounds.y() : std::max(0.0f, -bounds.y() - ascent));
-        bottom = ceilf(computeBounds ? bounds.maxY() : std::max(0.0f, bounds.maxY() - descent));
+        top = ceilf(std::max(0.0f, -bounds.y() - ascent));
+        bottom = ceilf(std::max(0.0f, bounds.maxY() - descent));
         left = ceilf(std::max(0.0f, -bounds.x()));
         right = ceilf(std::max(0.0f, bounds.maxX() - textWidth));
     }
 
-    // If computeBounds, top and bottom are the maximum heights of the glyphs above and below the baseline, respectively.
-    // Otherwise they are the amounts of glyph overflows exceeding the font metrics' ascent and descent, respectively.
+    // Top and bottom are the amounts of glyph overflows exceeding the font metrics' ascent and descent, respectively.
     // Left and right are the amounts of glyph overflows exceeding the left and right edge of normal layout boundary, respectively.
     // All fields are in absolute number of pixels rounded up to the nearest integer.
     int left;
     int right;
     int top;
     int bottom;
-    bool computeBounds;
 };
 
 } // namespace blink
 
 #endif // GlyphOverflow_h