MemoryCache: Enable MemoryCache to have multiple isolated resource maps

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 151 matching lines @@
 
     int serviceWorkerID() const;
 
     enum ResourceLoadStartType {
         ResourceLoadingFromNetwork,
         ResourceLoadingFromCache
     };
     void maybeNotifyInsecureContent(const Resource*) const;
     void requestLoadStarted(Resource*, const FetchRequest&, ResourceLoadStartType);
     static const ResourceLoaderOptions& defaultResourceOptions();
+
+    String createCacheIdentifier() const;
+
 private:
-
     explicit ResourceFetcher(DocumentLoader*);
 
     bool shouldLoadNewResource(Resource::Type) const;
 
     ResourcePtr<Resource> requestResource(Resource::Type, FetchRequest&);
     ResourcePtr<Resource> createResourceForRevalidation(const FetchRequest&, Resource*);
     ResourcePtr<Resource> createResourceForLoading(Resource::Type, FetchRequest&, const String& charset);
     void preCacheDataURIImage(const FetchRequest&);
     void preCacheSubstituteDataForMainResource(const FetchRequest&, const SubstituteData&);
     void storeResourceTimingInitiatorInformation(Resource*);
@@ skipping 83 matching lines @@
             m_loader->m_allowStaleResources = m_previousState;
     }
 private:
     ResourceFetcher* m_loader;
     bool m_previousState;
 };
 
 } // namespace blink
 
 #endif