[NotLanded] Implement the fetching algorithm of the Web Manifest.

Source/core/fetch/ResourceFetcher.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@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
     version 2 of the License, or (at your option) any later version.
@@ skipping 79 matching lines @@
     ResourcePtr<ScriptResource> fetchScript(FetchRequest&);
     ResourcePtr<FontResource> fetchFont(FetchRequest&);
     ResourcePtr<RawResource> fetchRawResource(FetchRequest&);
     ResourcePtr<RawResource> fetchMainResource(FetchRequest&, const SubstituteData&);
     ResourcePtr<DocumentResource> fetchSVGDocument(FetchRequest&);
     ResourcePtr<XSLStyleSheetResource> fetchXSLStyleSheet(FetchRequest&);
     ResourcePtr<Resource> fetchLinkResource(Resource::Type, FetchRequest&);
     ResourcePtr<RawResource> fetchImport(FetchRequest&);
     ResourcePtr<RawResource> fetchMedia(FetchRequest&);
     ResourcePtr<RawResource> fetchTextTrack(FetchRequest&);
+    ResourcePtr<Resource> fetchManifest(FetchRequest&);
 
     // Logs an access denied message to the console for the specified URL.
     void printAccessDeniedMessage(const KURL&) const;
 
     Resource* cachedResource(const KURL&) const;
 
     typedef HashMap<String, ResourcePtr<Resource> > DocumentResourceMap;
     const DocumentResourceMap& allResources() const { return m_documentResources; }
 
     bool autoLoadImages() const { return m_autoLoadImages; }
@@ skipping 155 matching lines @@
             m_loader->m_allowStaleResources = m_previousState;
     }
 private:
     ResourceFetcher* m_loader;
     bool m_previousState;
 };
 
 } // namespace blink
 
 #endif