Reland r113263 rebased after revert of r113249.

net/disk_cache/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_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_BACKEND_IMPL_H_
 #pragma once
 
@@ skipping 259 matching lines @@
                                  const base::Time end_time,
                                  OldCompletionCallback* callback) OVERRIDE;
   virtual int DoomEntriesBetween(
       const base::Time initial_time,
       const base::Time end_time,
       const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntriesSince(const base::Time initial_time,
                                OldCompletionCallback* callback) OVERRIDE;
   virtual int OpenNextEntry(void** iter, Entry** next_entry,
                             OldCompletionCallback* callback) OVERRIDE;
+  virtual int OpenNextEntry(void** iter, Entry** next_entry,
+                            const net::CompletionCallback& callback) OVERRIDE;
   virtual void EndEnumeration(void** iter) OVERRIDE;
   virtual void GetStats(StatsItems* stats) OVERRIDE;
   virtual void OnExternalCacheHit(const std::string& key) OVERRIDE;
 
  private:
   typedef base::hash_map<CacheAddr, EntryImpl*> EntriesMap;
 
   // Creates a new backing file for the cache index.
   bool CreateBackingStore(disk_cache::File* file);
   bool InitBackingStore(bool* file_created);
@@ skipping 105 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(BackendImpl);
 };
 
 // Returns the prefered max cache size given the available disk space.
 NET_EXPORT_PRIVATE int PreferedCacheSize(int64 available);
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_BACKEND_IMPL_H_