Refactoring: Simplify DocumentWriter by reorganizing its lifetime.

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 67 matching lines @@
         Frame* frame() const { return m_frame; }
 
         void detachFromFrame();
 
         FrameLoader* frameLoader() const;
 
         unsigned long mainResourceIdentifier() const;
 
         void replaceDocument(const String& source, Document*);
         DocumentWriter* beginWriting(const String& mimeType, const String& encoding, const KURL& = KURL());
+        void endWriting(DocumentWriter*);
+
         String mimeType() const;
 
         const ResourceRequest& originalRequest() const;
         const ResourceRequest& originalRequestCopy() const;
 
         const ResourceRequest& request() const;
         ResourceRequest& request();
 
         CachedResourceLoader* cachedResourceLoader() const { return m_cachedResourceLoader.get(); }
 
@@ skipping 57 matching lines @@
 
         virtual void reportMemoryUsage(MemoryObjectInfo*) const;
         void checkLoadComplete();
 
     protected:
         DocumentLoader(const ResourceRequest&, const SubstituteData&);
 
         bool m_deferMainResourceDataLoad;
 
     private:
+        static PassRefPtr<DocumentWriter> createWriterFor(Frame*, const Document* ownerDocument, const KURL&, const String& mimeType, const String& encoding, bool userChosen, bool dispatch);
+
+        void ensureWriter();
+        void ensureWriter(const String& mimeType, const KURL& overridingURL = KURL());
 
         // The URL of the document resulting from this DocumentLoader.
         KURL documentURL() const;
         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();
         PassRefPtr<SharedBuffer> mainResourceData() const;
 
-        bool maybeCreateArchive();
+        void createArchive();
         void clearArchiveResources();
 
         void prepareSubframeArchiveLoadIfNeeded();
         void addAllArchiveResources(MHTMLArchive*);
 
         void willSendRequest(ResourceRequest&, const ResourceResponse&);
         void finishedLoading(double finishTime);
         void mainReceivedError(const ResourceError&);
         virtual void redirectReceived(CachedResource*, ResourceRequest&, const ResourceResponse&) OVERRIDE;
         virtual void responseReceived(CachedResource*, const ResourceResponse&) OVERRIDE;
@@ skipping 14 matching lines @@
         void handleSubstituteDataLoadNow(DocumentLoaderTimer*);
         void startDataLoadTimer();
                 
         Frame* m_frame;
         RefPtr<CachedResourceLoader> m_cachedResourceLoader;
 
         CachedResourceHandle<CachedRawResource> m_mainResource;
         ResourceLoaderSet m_resourceLoaders;
         ResourceLoaderSet m_multipartResourceLoaders;
         
-        mutable DocumentWriter m_writer;
+        RefPtr<DocumentWriter> m_writer;
 
         // A reference to actual request used to create the data source.
         // This should only be used by the resourceLoadDelegate's
         // identifierForInitialRequest:fromDatasource: method. It is
         // not guaranteed to remain unchanged, as requests are mutable.
         ResourceRequest m_originalRequest;   
 
         SubstituteData m_substituteData;
 
         // A copy of the original request used to create the data source.
         // We have to copy the request because requests are mutable.
         ResourceRequest m_originalRequestCopy;
         
         // The 'working' request. It may be mutated
         // several times from the original request to include additional
         // headers, cookie information, canonicalization and redirects.
         ResourceRequest m_request;
 
         ResourceResponse m_response;
     
         ResourceError m_mainDocumentError;    
 
         bool m_committed;
         bool m_isStopping;
-        bool m_gotFirstByte;
         bool m_isClientRedirect;
 
         // FIXME: Document::m_processingLoadEvent and DocumentLoader::m_wasOnloadHandled are roughly the same
         // and should be merged.
         bool m_wasOnloadHandled;
 
         StringWithDirection m_pageTitle;
 
         String m_overrideEncoding;
 
@@ skipping 11 matching lines @@
         unsigned long m_identifierForLoadWithoutResourceLoader;
 
         DocumentLoaderTimer m_dataLoadTimer;
 
         friend class ApplicationCacheHost;  // for substitute resource delivery
         OwnPtr<ApplicationCacheHost> m_applicationCacheHost;
     };
 }
 
 #endif // DocumentLoader_h