Refactor http cache removing from a StoragePartition into separate class:

chrome/browser/browsing_data/storage_partition_http_cache_data_remover.h

+// Copyright 2015 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 CHROME_BROWSER_BROWSING_DATA_STORAGE_PARTITION_HTTP_CACHE_DATA_REMOVER_H_
+#define CHROME_BROWSER_BROWSING_DATA_STORAGE_PARTITION_HTTP_CACHE_DATA_REMOVER_H_
+
+#include "base/callback.h"
+#include "base/sequenced_task_runner_helpers.h"
+#include "base/time/time.h"
+
+namespace content {
+class StoragePartition;
+}
+
+namespace disk_cache {
+class Backend;
+}
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+// Helper to remove http cache data from a StoragePartition.
+class StoragePartitionHttpCacheDataRemover {
+ public:
+  static StoragePartitionHttpCacheDataRemover* CreateForRange(
+      content::StoragePartition* storage_partition,
+      base::Time delete_begin,
+      base::Time delete_end);
+
+  // Calls |done_callback| upon completion and also destroys itself.
+  void Remove(const base::Closure& done_callback);
+
+ private:
+  enum CacheState {
+    STATE_NONE,
+    STATE_CREATE_MAIN,
+    STATE_CREATE_MEDIA,
+    STATE_DELETE_MAIN,
+    STATE_DELETE_MEDIA,
+    STATE_DONE
+  };
+
+  StoragePartitionHttpCacheDataRemover(
+      base::Time delete_begin,
+      base::Time delete_end,
+      net::URLRequestContextGetter* main_context_getter,
+      net::URLRequestContextGetter* media_context_getter);
+
+  // StoragePartitionHttpCacheDataRemover deletes itself (using DeleteHelper)
+  // and is not supposed to be deleted by other objects so make destructor
+  // private and DeleteHelper a friend.
+  friend class base::DeleteHelper<StoragePartitionHttpCacheDataRemover>;
+
+  ~StoragePartitionHttpCacheDataRemover();
+
+  void ClearHttpCacheOnIOThread();
+  void ClearedHttpCache();
+  // Performs the actual work to delete the cache.
+  void DoClearCache(int rv);
+
+  const base::Time delete_begin_;
+  const base::Time delete_end_;
+
+  const scoped_refptr<net::URLRequestContextGetter> main_context_getter_;
+  const scoped_refptr<net::URLRequestContextGetter> media_context_getter_;
+
+  base::Closure done_callback_;
+
+  // IO.
+  int next_cache_state_;
+  disk_cache::Backend* cache_;
+
+  DISALLOW_COPY_AND_ASSIGN(StoragePartitionHttpCacheDataRemover);
+};
+
+#endif  // CHROME_BROWSER_BROWSING_DATA_STORAGE_PARTITION_HTTP_CACHE_DATA_REMOVER_H_