Refactor cache counting into a separate helper class

chrome/browser/browsing_data/cache_test_util.h

+// Copyright 2016 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_CACHE_TEST_UTIL_H_
+#define CHROME_BROWSER_BROWSING_DATA_CACHE_TEST_UTIL_H_
+
+#include <set>
+#include <vector>
+#include "base/run_loop.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/storage_partition.h"
+#include "net/disk_cache/disk_cache.h"
+
+using content::BrowserThread;
+
+// A util class that can be used to create and retreive cache entries.
+class CacheTestUtil {
+ public:
+  explicit CacheTestUtil(content::StoragePartition* partition_);
+
+  ~CacheTestUtil();
+
+  void CreateCacheEntries(const std::set<std::string>& keys);
+
+  std::vector<std::string> GetEntryKeys();
+
+  content::StoragePartition* partition() { return partition_; }
+  disk_cache::Backend* backend() { return backend_; }
+
+ private:
+  void SetUpOnIOThread();
+  void TearDownOnIOThread();
+
+  void CreateCacheEntriesOnIOThread(const std::set<std::string>& keys);
+
+  void GetEntryKeysOnIOThread();
+  void GetNextKey(int error);
+
+  void WaitForTasksOnIOThread();
+  void WaitForCompletion(int value);
+  void SetNumberOfWaitedTasks(int count);
+
+  void DoneCallback(int value);
+
+  base::Callback<void(int)> done_callback_;
+
+  content::StoragePartition* partition_;
+  disk_cache::Backend* backend_ = nullptr;
+  std::vector<disk_cache::Entry*> entries_;
+  std::unique_ptr<disk_cache::Backend::Iterator> iterator_;
+
+  disk_cache::Entry* current_entry_;
+  std::vector<std::string> keys_;
+
+  std::unique_ptr<base::WaitableEvent> waitable_event_;
+  int remaining_tasks_;
+};
+
+#endif  // CHROME_BROWSER_BROWSING_DATA_CACHE_TEST_UTIL_H_