Table with fixed layout behaves like auto layout when its width is set by js instead of css.

Source/core/rendering/style/RenderStyle.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, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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 545 matching lines @@
     const Length& clipRight() const { return visual->clip.right(); }
     const Length& clipTop() const { return visual->clip.top(); }
     const Length& clipBottom() const { return visual->clip.bottom(); }
     const LengthBox& clip() const { return visual->clip; }
     bool hasClip() const { return visual->hasClip; }
 
     EUnicodeBidi unicodeBidi() const { return static_cast<EUnicodeBidi>(noninherited_flags._unicodeBidi); }
 
     EClear clear() const { return static_cast<EClear>(noninherited_flags._clear); }
     ETableLayout tableLayout() const { return static_cast<ETableLayout>(noninherited_flags._table_layout); }
+    bool isFixedTableLayout() const { return tableLayout() == TFIXED && !logicalWidth().isAuto(); }
 
     const Font& font() const;
     const FontMetrics& fontMetrics() const;
     const FontDescription& fontDescription() const;
     float specifiedFontSize() const;
     float computedFontSize() const;
     int fontSize() const;
     FontWeight fontWeight() const;
 
     float textAutosizingMultiplier() const { return visual->m_textAutosizingMultiplier; }
@@ skipping 1299 matching lines @@
 inline bool RenderStyle::hasPseudoElementStyle() const
 {
     return noninherited_flags._pseudoBits & PSEUDO_ELEMENT_MASK;
 }
 
 float calcBorderRadiiConstraintScaleFor(const FloatRect&, const FloatRoundedRect::Radii&);
 
 } // namespace WebCore
 
 #endif // RenderStyle_h