Implement Blink-side changes to enable V8 code caching.

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 176 matching lines @@
     const ResourceResponse& response() const { return m_response; }
 
     // Sets the serialized metadata retrieved from the platform's cache.
     void setSerializedCachedMetadata(const char*, size_t);
 
     // Caches the given metadata in association with this resource and suggests
     // that the platform persist it. The dataTypeID is a pseudo-randomly chosen
     // identifier that is used to distinguish data generated by the caller.
     void setCachedMetadata(unsigned dataTypeID, const char*, size_t);
 
+    // Reset existing metadata, to allow setting new data.
+    void clearCachedMetadata();
+
     // Returns cached metadata of the given type associated with this resource.
     CachedMetadata* cachedMetadata(unsigned dataTypeID) const;
 
     bool hasOneHandle() const;
     bool canDelete() const;
 
     // List of acceptable MIME types separated by ",".
     // A MIME type may contain a wildcard, e.g. "text/*".
     AtomicString accept() const { return m_accept; }
     void setAccept(const AtomicString& accept) { m_accept = accept; }
@@ skipping 196 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