Fix 'text-underline-position: under' to use em height ascent/descent

third_party/WebKit/Source/core/layout/line/InlineFlowBox.h

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *
  * 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
@@ skipping 374 matching lines @@
       const LayoutRect& logical_visual_overflow,
       LayoutUnit line_top,
       LayoutUnit line_bottom) {
     // If we are setting an overflow, then we can't pretend not to have an
     // overflow.
     ClearKnownToHaveNoOverflow();
     SetOverflowFromLogicalRects(logical_layout_overflow,
                                 logical_visual_overflow, line_top, line_bottom);
   }
 
-  LayoutUnit MaxLogicalBottomForUnderline(LineLayoutItem decoration_object,
-                                          LayoutUnit max_logical_bottom) const;
-  LayoutUnit MinLogicalTopForUnderline(LineLayoutItem decoration_object,
-                                       LayoutUnit min_logical_top) const;
+  LayoutUnit FarthestPositionForUnderline(LineLayoutItem decorating_box,
+                                          LineVerticalPositionType,
+                                          FontBaseline,
+                                          LayoutUnit current) const;
 
  private:
   void PlaceBoxRangeInInlineDirection(InlineBox* first_child,
                                       InlineBox* last_child,
                                       LayoutUnit& logical_left,
                                       LayoutUnit& min_logical_left,
                                       LayoutUnit& max_logical_right,
                                       bool& needs_word_spacing);
   void BeginPlacingBoxRangesInInlineDirection(LayoutUnit logical_left) {
     SetLogicalLeft(logical_left);
@@ skipping 80 matching lines @@
 
 inline void InlineFlowBox::SetHasBadChildList() {
 #if DCHECK_IS_ON()
   has_bad_child_list_ = true;
 #endif
 }
 
 }  // namespace blink
 
 #endif  // InlineFlowBox_h