Add a UA style, "display: contents", for <slot>

third_party/WebKit/Source/core/css/CSSDefaultStyleSheets.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2013 Google 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.
@@ skipping 43 matching lines @@
   StyleSheetContents* defaultStyleSheet() { return m_defaultStyleSheet.get(); }
   StyleSheetContents* quirksStyleSheet() { return m_quirksStyleSheet.get(); }
   StyleSheetContents* svgStyleSheet() { return m_svgStyleSheet.get(); }
   StyleSheetContents* mathmlStyleSheet() { return m_mathmlStyleSheet.get(); }
   StyleSheetContents* mediaControlsStyleSheet() {
     return m_mediaControlsStyleSheet.get();
   }
   StyleSheetContents* fullscreenStyleSheet() {
     return m_fullscreenStyleSheet.get();
   }
+  StyleSheetContents* slotStyleSheet() { return m_slotStyleSheet.get(); }
 
   DECLARE_TRACE();
 
  private:
   CSSDefaultStyleSheets();
 
   Member<RuleSet> m_defaultStyle;
   Member<RuleSet> m_defaultQuirksStyle;
   Member<RuleSet> m_defaultPrintStyle;
   Member<RuleSet> m_defaultViewSourceStyle;
 
   Member<StyleSheetContents> m_defaultStyleSheet;
   Member<StyleSheetContents> m_mobileViewportStyleSheet;
   Member<StyleSheetContents> m_televisionViewportStyleSheet;
   Member<StyleSheetContents> m_xhtmlMobileProfileStyleSheet;
   Member<StyleSheetContents> m_quirksStyleSheet;
   Member<StyleSheetContents> m_svgStyleSheet;
   Member<StyleSheetContents> m_mathmlStyleSheet;
   Member<StyleSheetContents> m_mediaControlsStyleSheet;
   Member<StyleSheetContents> m_fullscreenStyleSheet;
+  Member<StyleSheetContents> m_slotStyleSheet;
 };
 
 }  // namespace blink
 
 #endif  // CSSDefaultStyleSheets_h