MemoryCache: Enable MemoryCache to have multiple isolated resource maps

Source/core/fetch/Resource.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, 2009, 2010, 2011 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 225 matching lines @@
     bool canUseCacheValidator();
     bool isCacheValidator() const { return m_resourceToRevalidate; }
     Resource* resourceToRevalidate() const { return m_resourceToRevalidate; }
     void setResourceToRevalidate(Resource*);
     bool hasCacheControlNoStoreHeader();
 
     bool isPurgeable() const;
     bool wasPurged() const;
     bool lock();
 
+    void setCacheIdentifier(const String& cacheIdentifier) { m_cacheIdentifier = cacheIdentifier; }
+    String cacheIdentifier() const { return m_cacheIdentifier; };
+
     virtual void didSendData(unsigned long long /* bytesSent */, unsigned long long /* totalBytesToBeSent */) { }
     virtual void didDownloadData(int) { }
 
     double loadFinishTime() const { return m_loadFinishTime; }
 
     virtual bool canReuse(const ResourceRequest&) const { return true; }
 
     // Used by the MemoryCache to reduce the memory consumption of the entry.
     void prune();
 
@@ skipping 112 matching lines @@
     double m_loadFinishTime;
 
     unsigned long m_identifier;
 
     size_t m_encodedSize;
     size_t m_decodedSize;
     unsigned m_handleCount;
     unsigned m_preloadCount;
     unsigned m_protectorCount;
 
+    String m_cacheIdentifier;
+
     unsigned m_preloadResult : 2; // PreloadResult
     unsigned m_requestedFromNetworkingLayer : 1;
 
     unsigned m_loading : 1;
 
     unsigned m_switchingClientsToRevalidatedResource : 1;
 
     unsigned m_type : 4; // Type
     unsigned m_status : 3; // Status
 
@@ skipping 28 matching lines @@
 const char* ResourceTypeName(Resource::Type);
 #endif
 
 #define DEFINE_RESOURCE_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName##Resource, Resource, resource, resource->type() == Resource::typeName, resource.type() == Resource::typeName); \
     inline typeName##Resource* to##typeName##Resource(const ResourcePtr<Resource>& ptr) { return to##typeName##Resource(ptr.get()); }
 
 }
 
 #endif