Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/blockfile/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_BLOCKFILE_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_BLOCKFILE_BACKEND_IMPL_H_
 
 #include "base/containers/hash_tables.h"
@@ skipping 55 matching lines @@
   int SyncInit();
   void CleanupCache();
 
   // Synchronous implementation of the asynchronous interface.
   int SyncOpenEntry(const std::string& key, Entry** entry);
   int SyncCreateEntry(const std::string& key, Entry** entry);
   int SyncDoomEntry(const std::string& key);
   int SyncDoomAllEntries();
   int SyncDoomEntriesBetween(base::Time initial_time,
                              base::Time end_time);
+  int SyncCalculateSizeOfAllEntries();
   int SyncDoomEntriesSince(base::Time initial_time);
   int SyncOpenNextEntry(Rankings::Iterator* iterator, Entry** next_entry);
   void SyncEndEnumeration(scoped_ptr<Rankings::Iterator> iterator);
   void SyncOnExternalCacheHit(const std::string& key);
 
   // Open or create an entry for the given |key| or |iter|.
   EntryImpl* OpenEntryImpl(const std::string& key);
   EntryImpl* CreateEntryImpl(const std::string& key);
   EntryImpl* OpenNextEntryImpl(Rankings::Iterator* iter);
 
@@ skipping 182 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;
   // NOTE: The blockfile Backend::Iterator::OpenNextEntry method does not modify
   // the last_used field of the entry, and therefore it does not impact the
   // eviction ranking of the entry. However, an enumeration will go through all
   // entries on the cache only if the cache is not modified while the
   // enumeration is taking place. Significantly altering the entry pointed by
   // the iterator (for example, deleting the entry) will invalidate the
   // iterator. Performing operations on an entry that modify the entry may
   // result in loops in the iteration, skipped entries or similar.
   scoped_ptr<Iterator> CreateIterator() override;
   void GetStats(StatsItems* stats) override;
@@ skipping 111 matching lines @@
   base::WaitableEvent done_;  // Signals the end of background work.
   scoped_refptr<TraceObject> trace_object_;  // Initializes internal tracing.
   base::WeakPtrFactory<BackendImpl> ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BackendImpl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_BLOCKFILE_BACKEND_IMPL_H_