Inform disk cache of WebKit memory cache hits.

net/http/http_transaction.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_HTTP_HTTP_TRANSACTION_H_
 #define NET_HTTP_HTTP_TRANSACTION_H_
 #pragma once
 
 #include "base/string16.h"
 #include "net/base/completion_callback.h"
@@ skipping 93 matching lines @@
   virtual LoadState GetLoadState() const = 0;
 
   // Returns the upload progress in bytes.  If there is no upload data,
   // zero will be returned.  This does not include the request headers.
   virtual uint64 GetUploadProgress() const = 0;
 
   // SetSSLHostInfo sets a object which reads and writes public information
   // about an SSL server. It's used to implement Snap Start.
   // TODO(agl): remove this.
   virtual void SetSSLHostInfo(SSLHostInfo*) { };
+
+  // For cache transactions, improves the rank of this entry in the LRU cache
+  // as if it had been used directly. This allows feedback from the renderer's
+  // memory cache to improve the selection of resources in the disk cache.
+  virtual void UpdateRankForExternalCacheHit() = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_TRANSACTION_H_