Don't expose DocumentWriter to embedding layer

Source/core/loader/DocumentLoader.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2011 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.
@@ skipping 62 matching lines @@
         void setFrame(Frame*);
         Frame* frame() const { return m_frame; }
 
         void detachFromFrame();
 
         FrameLoader* frameLoader() const;
 
         unsigned long mainResourceIdentifier() const;
 
         void replaceDocument(const String& source, Document*);
-        DocumentWriter* beginWriting(const AtomicString& mimeType, const AtomicString& encoding, const KURL& = KURL());
-        void endWriting(DocumentWriter*);
 
         const AtomicString& mimeType() const;
 
         void setUserChosenEncoding(const String& charset);
 
         const ResourceRequest& originalRequest() const;
         const ResourceRequest& originalRequestCopy() const;
 
         const ResourceRequest& request() const;
         ResourceRequest& request();
@@ skipping 62 matching lines @@
     protected:
         DocumentLoader(const ResourceRequest&, const SubstituteData&);
 
         Vector<KURL> m_redirectChain;
 
     private:
         static PassRefPtr<DocumentWriter> createWriterFor(Frame*, const Document* ownerDocument, const KURL&, const AtomicString& mimeType, const AtomicString& encoding, bool userChosen, bool dispatch);
 
         void ensureWriter();
         void ensureWriter(const AtomicString& mimeType, const KURL& overridingURL = KURL());
+        void endWriting(DocumentWriter*);
 
         Document* document() const;
 
-        void setRequest(const ResourceRequest&);
-
         void commitIfReady();
         void commitData(const char* bytes, size_t length);
         void setMainDocumentError(const ResourceError&);
         void clearMainResourceLoader();
         ResourceLoader* mainResourceLoader() const;
         void clearMainResourceHandle();
 
         void createArchive();
         void clearArchiveResources();
 
@@ skipping 59 matching lines @@
         DocumentLoadTiming m_documentLoadTiming;
 
         double m_timeOfLastDataReceived;
 
         friend class ApplicationCacheHost;  // for substitute resource delivery
         OwnPtr<ApplicationCacheHost> m_applicationCacheHost;
     };
 }
 
 #endif // DocumentLoader_h