Remove bad const from disk_cache::Backend interface.

net/disk_cache/mem_backend_impl.h

 // Copyright (c) 2012 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__
 
 #include "base/compiler_specific.h"
@@ skipping 53 matching lines @@
   // Backend interface.
   virtual net::CacheType GetCacheType() const OVERRIDE;
   virtual int32 GetEntryCount() const OVERRIDE;
   virtual int OpenEntry(const std::string& key, Entry** entry,
                         const CompletionCallback& callback) OVERRIDE;
   virtual int CreateEntry(const std::string& key, Entry** entry,
                           const CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntry(const std::string& key,
                         const CompletionCallback& callback) OVERRIDE;
   virtual int DoomAllEntries(const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomEntriesBetween(const base::Time initial_time,
-                                 const base::Time end_time,
+  virtual int DoomEntriesBetween(base::Time initial_time,
+                                 base::Time end_time,
                                  const CompletionCallback& callback) OVERRIDE;
-  virtual int DoomEntriesSince(const base::Time initial_time,
+  virtual int DoomEntriesSince(base::Time initial_time,
                                const CompletionCallback& callback) OVERRIDE;
   virtual int OpenNextEntry(void** iter, Entry** next_entry,
                             const CompletionCallback& callback) OVERRIDE;
   virtual void EndEnumeration(void** iter) OVERRIDE;
   virtual void GetStats(
       std::vector<std::pair<std::string, std::string> >* stats) OVERRIDE {}
   virtual void OnExternalCacheHit(const std::string& key) OVERRIDE;
 
  private:
   typedef base::hash_map<std::string, MemEntryImpl*> EntryMap;
@@ skipping 23 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__