Don't expose DocumentWriter to embedding layer

Source/core/fetch/ResourceFetcher.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 358 matching lines @@
 ResourcePtr<RawResource> ResourceFetcher::fetchMainResource(FetchRequest& request, const SubstituteData& substituteData)
 {
     if (substituteData.isValid())
         preCacheSubstituteDataForMainResource(request, substituteData);
     return toRawResource(requestResource(Resource::MainResource, request));
 }
 
 void ResourceFetcher::preCacheSubstituteDataForMainResource(const FetchRequest& request, const SubstituteData& substituteData)
 {
     const KURL& url = request.url();
-    ASSERT(!memoryCache()->resourceForURL(url));
+    if (Resource* oldResource = memoryCache()->resourceForURL(url))
+        memoryCache()->remove(oldResource);
 
     ResourceResponse response(url, substituteData.mimeType(), substituteData.content()->size(), substituteData.textEncoding(), emptyString());
     ResourcePtr<Resource> resource = createResource(Resource::MainResource, request.resourceRequest(), substituteData.textEncoding());
+    resource->setNeedsSynchronousCacheHit(substituteData.forceSynchronousLoad());
     resource->setOptions(request.options());
     resource->setDataBufferingPolicy(BufferData);
     resource->responseReceived(response);
     if (substituteData.content()->size())
         resource->setResourceBuffer(substituteData.content());
     resource->finish();
     memoryCache()->add(resource.get());
 }
 
 bool ResourceFetcher::checkInsecureContent(Resource::Type type, const KURL& url, MixedContentBlockingTreatment treatment) const
@@ skipping 952 matching lines @@
 }
 #endif
 
 const ResourceLoaderOptions& ResourceFetcher::defaultResourceOptions()
 {
     DEFINE_STATIC_LOCAL(ResourceLoaderOptions, options, (SniffContent, BufferData, AllowStoredCredentials, ClientRequestedCredentials, AskClientForCrossOriginCredentials, DoSecurityCheck, CheckContentSecurityPolicy, DocumentContext));
     return options;
 }
 
 }