Implement ::content

Source/core/css/CSSSelector.h

Index: Source/core/css/CSSSelector.h
diff --git a/Source/core/css/CSSSelector.h b/Source/core/css/CSSSelector.h
index 2e562621c8e2f25323a986bb1f0ade86125ce66d..c048269b163dd535a0e25a2232947bd618c8db8f 100644
--- a/Source/core/css/CSSSelector.h
+++ b/Source/core/css/CSSSelector.h
@@ -162,7 +162,8 @@ namespace WebCore {
             PseudoPastCue,
             PseudoSeamlessDocument,
             PseudoDistributed,
-            PseudoUnresolved
+            PseudoUnresolved,
+            PseudoContent
         };
 
         enum MarginBoxType {
@@ -218,6 +219,7 @@ namespace WebCore {
         bool isSiblingSelector() const;
         bool isAttributeSelector() const;
         bool isDistributedPseudoElement() const;
+        bool isContentPseudoElement() const;
 
         Relation relation() const { return static_cast<Relation>(m_relation); }
 
@@ -339,6 +341,11 @@ inline bool CSSSelector::isDistributedPseudoElement() const
     return m_match == PseudoElement && pseudoType() == PseudoDistributed;
 }
 
+inline bool CSSSelector::isContentPseudoElement() const
+{
+    return m_match == PseudoElement && pseudoType() == PseudoContent;
+}
+
 inline void CSSSelector::setValue(const AtomicString& value)
 {
     ASSERT(m_match != Tag);