Revert (4 of 4) 30153 - Introduce browser_sync::ExtensionsActivityMonitor to ...

chrome/browser/sync/util/extensions_activity_monitor.h

-// Copyright (c) 2009 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_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_
-#define CHROME_BROWSER_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_
-
-#include "base/lock.h"
-#include "base/message_loop.h"
-#include "base/ref_counted.h"
-#include "chrome/common/notification_observer.h"
-#include "chrome/common/notification_registrar.h"
-
-namespace browser_sync {
-
-// A class to monitor usage of extensions APIs to send to sync servers, with
-// the ability to purge data once sync servers have acknowledged it (successful
-// commit response).
-//
-// This can be used from any thread (it is a 'monitor' in the synchronization
-// sense as well), HOWEVER
-//
-// *** IT MUST BE DELETED FROM THE UI LOOP ***
-//
-// Consider using MessageLoop::DeleteSoon. (Yes, this means if you allocate
-// an ExtensionsActivityMonitor on a thread other than UI, you must 'new' it).
-class ExtensionsActivityMonitor : public NotificationObserver {
- public:
-  // A data record of activity performed by extension |extension_id|.
-  struct Record {
-    Record() : bookmark_write_count(0U) {}
-
-    // The human-readable ID identifying the extension responsible
-    // for the activity reported in this Record.
-    std::string extension_id;
-
-    // How many times the extension successfully invoked a write
-    // operation through the bookmarks API since the last CommitMessage.
-    uint32 bookmark_write_count;
-  };
-
-  typedef std::map<std::string, Record> Records;
-
-  // Creates an ExtensionsActivityMonitor to monitor extensions activities on
-  // |ui_loop|.
-  explicit ExtensionsActivityMonitor(MessageLoop* ui_loop);
-  ~ExtensionsActivityMonitor();
-
-  // Fills |buffer| with snapshot of current records in constant time by
-  // swapping.  This is done mutually exclusively w.r.t methods of this class.
-  void GetAndClearRecords(Records* buffer);
-
-  // Add |records| piece-wise (by extension id) to the set of active records.
-  // This is done mutually exclusively w.r.t the methods of this class.
-  void PutRecords(const Records& records);
-
-  // NotificationObserver implementation.  Called on |ui_loop_|.
-  virtual void Observe(NotificationType type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details);
- private:
-  Records records_;
-  mutable Lock records_lock_;
-
-  // Kept for convenience.
-  MessageLoop* const ui_loop_;
-
-  // Used only from UI loop.
-  NotificationRegistrar registrar_;
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_