Remove an unneccessary FIXME comment for HTMLToken

Source/core/html/parser/AtomicHTMLToken.h

Index: Source/core/html/parser/AtomicHTMLToken.h
diff --git a/Source/core/html/parser/AtomicHTMLToken.h b/Source/core/html/parser/AtomicHTMLToken.h
index dc0e54eb48ba86845404c4648c690af4547c2af4..68aa2ff1543022f7213e4dba299a8ac4dd47fa1e 100644
--- a/Source/core/html/parser/AtomicHTMLToken.h
+++ b/Source/core/html/parser/AtomicHTMLToken.h
@@ -96,14 +96,14 @@ public:
     }
 
     // FIXME: Distinguish between a missing public identifer and an empty one.
-    Vector<UChar>& publicIdentifier() const
+    String& publicIdentifier() const
     {
         ASSERT(m_type == HTMLToken::DOCTYPE);
         return m_doctypeData->m_publicIdentifier;
     }
 
     // FIXME: Distinguish between a missing system identifer and an empty one.
-    Vector<UChar>& systemIdentifier() const
+    String& systemIdentifier() const
     {
         ASSERT(m_type == HTMLToken::DOCTYPE);
         return m_doctypeData->m_systemIdentifier;
@@ -153,9 +153,9 @@ public:
             m_name = AtomicString(token.data());
             m_doctypeData = adoptPtr(new DoctypeData());
             m_doctypeData->m_hasPublicIdentifier = true;
-            append(m_doctypeData->m_publicIdentifier, token.publicIdentifier());
+            m_doctypeData->m_publicIdentifier = token.publicIdentifier();
             m_doctypeData->m_hasSystemIdentifier = true;
-            append(m_doctypeData->m_systemIdentifier, token.systemIdentifier());
+            m_doctypeData->m_systemIdentifier = token.systemIdentifier();
             m_doctypeData->m_forceQuirks = token.doctypeForcesQuirks();
             break;
         case HTMLToken::EndOfFile: