Convert XMLDocumentParser code to Use more reference

Source/core/xml/parser/XMLDocumentParser.h

Index: Source/core/xml/parser/XMLDocumentParser.h
diff --git a/Source/core/xml/parser/XMLDocumentParser.h b/Source/core/xml/parser/XMLDocumentParser.h
index 294c02d8cceea9b4a32603c05d1176b055df5002..2294720c35da9e93b8df92292263fc5ca9c7111a 100644
--- a/Source/core/xml/parser/XMLDocumentParser.h
+++ b/Source/core/xml/parser/XMLDocumentParser.h
@@ -66,7 +66,7 @@ class Text;
     class XMLDocumentParser FINAL : public ScriptableDocumentParser, public ResourceClient {
         WTF_MAKE_FAST_ALLOCATED;
     public:
-        static PassRefPtr<XMLDocumentParser> create(Document* document, FrameView* view)
+        static PassRefPtr<XMLDocumentParser> create(Document& document, FrameView* view)
         {
             return adoptRef(new XMLDocumentParser(document, view));
         }
@@ -101,7 +101,7 @@ class Text;
         };
 
     private:
-        XMLDocumentParser(Document*, FrameView* = 0);
+        explicit XMLDocumentParser(Document&, FrameView* = 0);
         XMLDocumentParser(DocumentFragment*, Element*, ParserContentPolicy);
 
         // From DocumentParser