Remove resource type-specific fetching logic from ResourceFetcher

Source/core/fetch/XSLStyleSheetResource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     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
     version 2 of the License, or (at your option) any later version.
@@ skipping 13 matching lines @@
 */
 
 #ifndef XSLStyleSheetResource_h
 #define XSLStyleSheetResource_h
 
 #include "core/fetch/ResourcePtr.h"
 #include "core/fetch/StyleSheetResource.h"
 
 namespace blink {
 
+class FetchRequest;
+class ResourceFetcher;
+
 class XSLStyleSheetResource final : public StyleSheetResource {
 public:
-    XSLStyleSheetResource(const ResourceRequest&, const String& charset);
+    static ResourcePtr<XSLStyleSheetResource> fetch(FetchRequest&, ResourceFetcher*);
 
     const String& sheet() const { return m_sheet; }
 
     virtual void didAddClient(ResourceClient*) override;
 
 protected:
+    class XSLStyleSheetResourceFactory : public ResourceFactory {
+    public:
+        XSLStyleSheetResourceFactory()
+            : ResourceFactory(Resource::XSLStyleSheet) { }
+
+        Resource* create(const ResourceRequest& request, const String& charset) const override
+        {
+            return new XSLStyleSheetResource(request, charset);
+        }
+    };
+    XSLStyleSheetResource(const ResourceRequest&, const String& charset);
+
     virtual void checkNotify() override;
 
     String m_sheet;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(XSLStyleSheet);
 
 } // namespace blink
 
 #endif