Convert XMLDocumentParser code to Use more reference

Source/core/dom/DecodedDataDocumentParser.h

 /*
  * Copyright (C) 2010 Google, Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 31 matching lines @@
     // The below functions are used by DocumentWriter (the loader).
     virtual void appendBytes(const char* bytes, size_t length) OVERRIDE;
     virtual void flush() OVERRIDE;
     virtual bool needsDecoder() const OVERRIDE FINAL { return m_needsDecoder; }
     virtual void setDecoder(PassOwnPtr<TextResourceDecoder>) OVERRIDE;
     virtual TextResourceDecoder* decoder() OVERRIDE FINAL;
 
     PassOwnPtr<TextResourceDecoder> takeDecoder();
 
 protected:
-    explicit DecodedDataDocumentParser(Document*);
+    explicit DecodedDataDocumentParser(Document&);
     virtual ~DecodedDataDocumentParser();
 
 private:
     // append is used by DocumentWriter::replaceDocument.
     virtual void append(PassRefPtr<StringImpl>) = 0;
 
     void updateDocument(String& decodedData);
 
     bool m_needsDecoder;
     OwnPtr<TextResourceDecoder> m_decoder;
 };
 
 }
 
 #endif // DecodedDataDocumentParser_h