[css-display] Support pseudo-elements on display: contents elements.

third_party/WebKit/Source/core/dom/Element.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003-2011, 2013, 2014 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
@@ skipping 618 matching lines @@
   void beginParsingChildren() { setIsFinishedParsingChildren(false); }
 
   PseudoElement* pseudoElement(PseudoId) const;
   LayoutObject* pseudoElementLayoutObject(PseudoId) const;
 
   ComputedStyle* pseudoStyle(const PseudoStyleRequest&,
                              const ComputedStyle* parentStyle = nullptr);
   PassRefPtr<ComputedStyle> getUncachedPseudoStyle(
       const PseudoStyleRequest&,
       const ComputedStyle* parentStyle = nullptr);
+  bool canGeneratePseudoElement(PseudoId) const;
 
   virtual bool matchesDefaultPseudoClass() const { return false; }
   virtual bool matchesEnabledPseudoClass() const { return false; }
   virtual bool matchesReadOnlyPseudoClass() const { return false; }
   virtual bool matchesReadWritePseudoClass() const { return false; }
   virtual bool matchesValidityPseudoClasses() const { return false; }
 
   // https://dom.spec.whatwg.org/#dom-element-matches
   bool matches(const AtomicString& selectors,
                ExceptionState& = ASSERT_NO_EXCEPTION);
@@ skipping 576 matching lines @@
 #define DECLARE_ELEMENT_FACTORY_WITH_TAGNAME(T) \
   static T* create(const QualifiedName&, Document&)
 #define DEFINE_ELEMENT_FACTORY_WITH_TAGNAME(T)                     \
   T* T::create(const QualifiedName& tagName, Document& document) { \
     return new T(tagName, document);                               \
   }
 
 }  // namespace blink
 
 #endif  // Element_h