Fix tab is invisible when the next stop is close

third_party/WebKit/Source/platform/fonts/Font.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
@@ skipping 176 matching lines @@
     return m_fontFallbackList ? m_fontFallbackList->getFontSelector() : 0;
 }
 
 inline float Font::tabWidth(const SimpleFontData& fontData, const TabSize& tabSize, float position) const
 {
     float baseTabWidth = tabSize.getPixelSize(fontData.spaceWidth());
     if (!baseTabWidth)
         return getFontDescription().letterSpacing();
     float distanceToTabStop = baseTabWidth - fmodf(position, baseTabWidth);
 
-    // The smallest allowable tab space is letterSpacing() (but must be at least one layout unit).
+    // Let the minimum width be the half of the space width so that it's always recognizable.
     // if the distance to the next tab stop is less than that, advance an additional tab stop.
-    if (distanceToTabStop < std::max(getFontDescription().letterSpacing(), LayoutUnit::epsilon()))
+    if (distanceToTabStop < fontData.spaceWidth() / 2)
         distanceToTabStop += baseTabWidth;
 
     return distanceToTabStop;
 }
 
 } // namespace blink
 
 #endif