Inform disk cache of WebKit memory cache hits.

net/disk_cache/mem_backend_impl.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.
 
 // See net/disk_cache/disk_cache.h for the public interface of the cache.
 
 #ifndef NET_DISK_CACHE_MEM_BACKEND_IMPL_H__
 #define NET_DISK_CACHE_MEM_BACKEND_IMPL_H__
 #pragma once
 
@@ skipping 62 matching lines @@
   virtual int DoomEntriesBetween(const base::Time initial_time,
                                  const base::Time end_time,
                                  CompletionCallback* callback);
   virtual int DoomEntriesSince(const base::Time initial_time,
                                CompletionCallback* callback);
   virtual int OpenNextEntry(void** iter, Entry** next_entry,
                             CompletionCallback* callback);
   virtual void EndEnumeration(void** iter);
   virtual void GetStats(
       std::vector<std::pair<std::string, std::string> >* stats) {}
+  virtual void OnExternalCacheHit(const std::string& key);
 
  private:
   typedef base::hash_map<std::string, MemEntryImpl*> EntryMap;
 
   // Old Backend interface.
   bool OpenEntry(const std::string& key, Entry** entry);
   bool CreateEntry(const std::string& key, Entry** entry);
   bool DoomEntry(const std::string& key);
   bool DoomAllEntries();
   bool DoomEntriesBetween(const base::Time initial_time,
@@ skipping 16 matching lines @@
   int32 current_size_;
 
   net::NetLog* net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(MemBackendImpl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_MEM_BACKEND_IMPL_H__