List marker pseudo elements.

Source/core/dom/PseudoElement.cpp

Index: Source/core/dom/PseudoElement.cpp
diff --git a/Source/core/dom/PseudoElement.cpp b/Source/core/dom/PseudoElement.cpp
index 2e3b2dee0ea756ef685027e4870b27e1cfdcf18f..bb210bf9b2df93d693faca61ab1ffcae18c8e01c 100644
--- a/Source/core/dom/PseudoElement.cpp
+++ b/Source/core/dom/PseudoElement.cpp
@@ -55,6 +55,10 @@ const QualifiedName& pseudoElementTagName(PseudoId pseudoId)
         DEFINE_STATIC_LOCAL(QualifiedName, backdrop, (nullAtom, "<pseudo:backdrop>", nullAtom));
         return backdrop;
     }
+    case MARKER: {
+        DEFINE_STATIC_LOCAL(QualifiedName, marker, (nullAtom, "<pseudo:marker>", nullAtom));
+        return marker;
+    }
     case FIRST_LETTER: {
         DEFINE_STATIC_LOCAL(QualifiedName, firstLetter, (nullAtom, "<pseudo:first-letter>", nullAtom));
         return firstLetter;