| // 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 COMPONENTS_SYNC_SESSIONS_SYNC_SESSIONS_METRICS_H_ |
| #define COMPONENTS_SYNC_SESSIONS_SYNC_SESSIONS_METRICS_H_ |
| |
| #include <vector> |
| |
| namespace base { |
| class Time; |
| } // namespace base |
| |
| namespace sync_sessions { |
| |
| class SessionsSyncManager; |
| struct SyncedSession; |
| |
| class SyncSessionsMetrics { |
| public: |
| // Records via an UMA histogram the age of the youngest foreign tab the given |
| // manager is aware of. No attempt is made to aquire a more recent version of |
| // world. If anything goes wrong, such as the manager being null, no foreign |
| // session present, or a foreign tab with a timestamp in the future then no |
| // metric is emitted. |
| static void RecordYoungestForeignTabAgeOnNTP( |
| SessionsSyncManager* sessions_sync_manager); |
| |
| private: |
| friend class SyncSessionsMetricsTest; |
| |
| // Returns the highest timestamp for any tab in the given sessions. Note that |
| // sessions should be sorted by timestamp, and session timestamps should |
| // always be greater or equal to children window/tab timestamps. No navigation |
| // timestamps are checked. |
| static base::Time MaxTabTimestamp( |
| const std::vector<const SyncedSession*>& sessions); |
| }; |
| |
| } // namespace sync_sessions |
| |
| #endif // COMPONENTS_SYNC_SESSIONS_SYNC_SESSIONS_METRICS_H_ |