Remove partial blockfile v3 disk_cache implementation.

net/disk_cache/blockfile/backend_worker_v3.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_WORKER_V3_H_
-#define NET_DISK_CACHE_BLOCKFILE_BACKEND_WORKER_V3_H_
-
-#include "base/containers/hash_tables.h"
-#include "base/files/file_path.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "net/disk_cache/blockfile/addr.h"
-#include "net/disk_cache/blockfile/backend_impl_v3.h"
-#include "net/disk_cache/blockfile/block_files.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
-namespace disk_cache {
-
-class BackendImplV3::Worker : public base::RefCountedThreadSafe<Worker> {
- public:
-  Worker(const base::FilePath& path,
-         const scoped_refptr<base::SingleThreadTaskRunner>& main_thread);
-
-  // Performs general initialization for this current instance of the cache.
-  int Init(const CompletionCallback& callback);
-
- private:
-  friend class base::RefCountedThreadSafe<Worker>;
-
-  ~Worker();
-  void CleanupCache();
-
-  // Returns the full name for an external storage file.
-  base::FilePath GetFileName(Addr address) const;
-
-  // Creates a new backing file for the cache index.
-  bool CreateBackingStore(disk_cache::File* file);
-  bool InitBackingStore(bool* file_created);
-
-  // Performs basic checks on the index file. Returns false on failure.
-  bool CheckIndex();
-
-  base::FilePath path_;  // Path to the folder used as backing storage.
-  BlockFiles block_files_;  // Set of files used to store all data.
-  bool init_;  // controls the initialization of the system.
-
-  DISALLOW_COPY_AND_ASSIGN(Worker);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_BLOCKFILE_BACKEND_WORKER_V3_H_