Clarify that there is no :cue or :cue(...) pseudo-class

Source/core/css/CSSSelector.cpp

 /*
  * Copyright (C) 1999-2003 Lars Knoll (knoll@kde.org)
  *               1999 Waldo Bastian (bastian@kde.org)
  *               2001 Andreas Schlapbach (schlpbch@iam.unibe.ch)
  *               2001-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 442 matching lines @@
 
     m_pseudoType = parsePseudoType(value(), !argument().isNull() || selectorList());
 
     bool element = false; // pseudo-element
     bool compat = false; // single colon compatbility mode
     bool isPagePseudoClass = false; // Page pseudo-class
 
     switch (m_pseudoType) {
     case PseudoAfter:
     case PseudoBefore:
-    case PseudoCue:
     case PseudoFirstLetter:
     case PseudoFirstLine:
         compat = true;
     case PseudoBackdrop:
+    case PseudoCue:
     case PseudoResizer:
     case PseudoScrollbar:
     case PseudoScrollbarCorner:
     case PseudoScrollbarButton:
     case PseudoScrollbarThumb:
     case PseudoScrollbarTrack:
     case PseudoScrollbarTrackPiece:
     case PseudoSelection:
     case PseudoWebKitCustomElement:
     case PseudoContent:
@@ skipping 430 matching lines @@
         if (count < nthBValue())
             return false;
         return (count - nthBValue()) % nthAValue() == 0;
     }
     if (count > nthBValue())
         return false;
     return (nthBValue() - count) % (-nthAValue()) == 0;
 }
 
 } // namespace blink