Disk Cache: Don't depend on the backend being enabled to...

net/disk_cache/entry_impl.h

 // Copyright (c) 2006-2009 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_DISK_CACHE_ENTRY_IMPL_H_
 #define NET_DISK_CACHE_ENTRY_IMPL_H_
 
 #include "base/scoped_ptr.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/disk_cache/storage_block.h"
@@ skipping 158 matching lines @@
   // Generates a histogram for the time spent working on this operation.
   void ReportIOTime(Operation op, const base::Time& start);
 
   // Logs this entry to the internal trace buffer.
   void Log(const char* msg);
 
   CacheEntryBlock entry_;     // Key related information for this entry.
   CacheRankingsBlock node_;   // Rankings related information for this entry.
   BackendImpl* backend_;      // Back pointer to the cache.
   scoped_array<char> user_buffers_[kNumStreams];  // Store user data.
-  scoped_refptr<File> files_[kNumStreams + 1];    // Files to store external
-                                                  // user data and key.
+  // Files to store external user data and key.
+  scoped_refptr<File> files_[kNumStreams + 1];
+  // Copy of the file used to store the key. We don't own this object.
+  mutable File* key_file_;
   int unreported_size_[kNumStreams];  // Bytes not reported yet to the backend.
   bool doomed_;               // True if this entry was removed from the cache.
   scoped_ptr<SparseControl> sparse_;  // Support for sparse entries.
 
   DISALLOW_EVIL_CONSTRUCTORS(EntryImpl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_ENTRY_IMPL_H_