[WIP] do something :-)

Source/core/style/StyleBoxData.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 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
  * 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.
  *
  */
 
 #include "config.h"
 #include "core/style/StyleBoxData.h"
 
 #include "core/style/ComputedStyle.h"
+#include "wtf/SizeAssertions.h"
 
 namespace blink {
 
-struct SameSizeAsStyleBoxData : public RefCounted<SameSizeAsStyleBoxData> {
-    Length length[7];
-    int m_zIndex;
-    uint32_t bitfields;
-};
-
-static_assert(sizeof(StyleBoxData) == sizeof(SameSizeAsStyleBoxData), "StyleBoxData should stay small");
+ASSERT_SIZE(StyleBoxData, 68, 68);
 
 StyleBoxData::StyleBoxData()
     : m_minWidth(ComputedStyle::initialMinSize())
     , m_maxWidth(ComputedStyle::initialMaxSize())
     , m_minHeight(ComputedStyle::initialMinSize())
     , m_maxHeight(ComputedStyle::initialMaxSize())
     , m_zIndex(0)
     , m_hasAutoZIndex(true)
     , m_boxSizing(CONTENT_BOX)
     , m_boxDecorationBreak(DSLICE)
@@ skipping 25 matching lines @@
         && m_minHeight == o.m_minHeight
         && m_maxHeight == o.m_maxHeight
         && m_verticalAlign == o.m_verticalAlign
         && m_zIndex == o.m_zIndex
         && m_hasAutoZIndex == o.m_hasAutoZIndex
         && m_boxSizing == o.m_boxSizing
         && m_boxDecorationBreak == o.m_boxDecorationBreak;
 }
 
 } // namespace blink