Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/simple/simple_backend_impl.h

 // Copyright (c) 2013 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_SIMPLE_SIMPLE_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_IMPL_H_
 
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 87 matching lines @@
                   Entry** entry,
                   const CompletionCallback& callback) override;
   int DoomEntry(const std::string& key,
                 const CompletionCallback& callback) override;
   int DoomAllEntries(const CompletionCallback& callback) override;
   int DoomEntriesBetween(base::Time initial_time,
                          base::Time end_time,
                          const CompletionCallback& callback) override;
   int DoomEntriesSince(base::Time initial_time,
                        const CompletionCallback& callback) override;
+  int CalculateSizeOfAllEntries(const CompletionCallback& callback) override;
   scoped_ptr<Iterator> CreateIterator() override;
   void GetStats(base::StringPairs* stats) override;
   void OnExternalCacheHit(const std::string& key) override;
 
  private:
   class SimpleIterator;
   friend class SimpleIterator;
 
   typedef base::hash_map<uint64, SimpleEntryImpl*> EntryMap;
 
@@ skipping 85 matching lines @@
   // is complete. The base::Closure map target is used to store deferred
   // operations to be run at the completion of the Doom.
   base::hash_map<uint64, std::vector<base::Closure> > entries_pending_doom_;
 
   net::NetLog* const net_log_;
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_IMPL_H_