Implement ::content

Source/core/css/SelectorChecker.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 75 matching lines @@
     if (context.selector->m_match == CSSSelector::PseudoElement) {
         if (context.selector->isCustomPseudoElement()) {
             if (ShadowRoot* root = context.element->containingShadowRoot()) {
                 if (context.element->shadowPseudoId() != context.selector->value())
                     return SelectorFailsLocally;
 
                 if (context.selector->pseudoType() == CSSSelector::PseudoWebKitCustomElement && root->type() != ShadowRoot::UserAgentShadowRoot)
                     return SelectorFailsLocally;
             } else
                 return SelectorFailsLocally;
+        } else if (context.selector->isContentPseudoElement()) {
+            if (!context.element->isInShadowTree() || !context.element->isInsertionPoint())
+                return SelectorFailsLocally;
         } else {
             if ((!context.elementStyle && m_mode == ResolvingStyle) || m_mode == QueryingRules)
                 return SelectorFailsLocally;
 
             PseudoId pseudoId = CSSSelector::pseudoId(context.selector->pseudoType());
             if (pseudoId == FIRST_LETTER) {
                 if (Document* document = context.element->document())
                     document->styleSheetCollection()->setUsesFirstLetterRules(true);
             }
             if (pseudoId != NOPSEUDO && m_mode != SharingRules)
@@ skipping 806 matching lines @@
     return element->focused() && isFrameFocused(element);
 }
 
 template
 SelectorChecker::Match SelectorChecker::match(const SelectorCheckingContext&, PseudoId&, const DOMSiblingTraversalStrategy&) const;
 
 template
 SelectorChecker::Match SelectorChecker::match(const SelectorCheckingContext&, PseudoId&, const ShadowDOMSiblingTraversalStrategy&) const;
 
 }