Show data usage on Site Details (MDSettings)

chrome/browser/storage/storage_info_fetcher.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_STORAGE_STORAGE_INFO_FETCHER_H_
+#define CHROME_BROWSER_STORAGE_STORAGE_INFO_FETCHER_H_
+
+#include "base/memory/ref_counted.h"
+#include "storage/browser/quota/quota_manager.h"
+
+// Asynchronously fetches the amount of storage used by websites.
+class StorageInfoFetcher :
+    public base::RefCountedThreadSafe<StorageInfoFetcher> {
+ public:
+  // Observer interface for monitoring StorageInfoFetcher.
+  class Observer {
+   public:
+    // Called when the storage has been calculated.
+    virtual void OnGetUsageInfo(const storage::UsageInfoEntries& entries) = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  explicit StorageInfoFetcher(storage::QuotaManager* quota_manager);
+
+  // Asynchronously fetches the StorageInfo.
+  void Run();
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+ private:
+  virtual ~StorageInfoFetcher();
+
+  friend class base::RefCountedThreadSafe<StorageInfoFetcher>;
+
+  // Fetches the usage information.
+  void GetUsageInfo(const storage::GetUsageInfoCallback& callback);
+
+  // Called when usage information is available.
+  void OnGetUsageInfoInternal(const storage::UsageInfoEntries& entries);
+
+  // Reports back to all observers that information is available.
+  void InvokeCallback();
+
+  // All clients observing this class.
+  base::ObserverList<Observer> observers_;
+
+  // The quota manager to use to calculate the storage usage.
+  storage::QuotaManager* quota_manager_;
+
+  // Hosts and their usage.
+  storage::UsageInfoEntries entries_;
+
+  DISALLOW_COPY_AND_ASSIGN(StorageInfoFetcher);
+};
+
+#endif  // CHROME_BROWSER_STORAGE_STORAGE_INFO_FETCHER_H_