[Chromoting] Retrieve process resource usage (ProcessStats) and its tests

remoting/host/forward_process_stats_agent.h

+// Copyright 2017 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 REMOTING_HOST_FORWARD_PROCESS_STATS_AGENT_H_
+#define REMOTING_HOST_FORWARD_PROCESS_STATS_AGENT_H_
+
+#include "base/synchronization/lock.h"
+#include "remoting/host/process_stats_agent.h"
+#include "remoting/proto/process_stats.pb.h"
+
+namespace remoting {
+namespace host {
+
+// A component to forward statistic data of another process.

[Sergey Ulanov, 2017/04/06 05:55:50]

It's not completely clear how this is supposed to be used. Particularly how will
the GetResourceUsage() is synchronized with OnProcessStats()?
Do you need it just for tests?

[Hzj_jie, 2017/04/06 19:41:05]

No, this class is designed to receive process usage from desktop process and
merges with the usage of network process.

+class ForwardProcessStatsAgent final : public ProcessStatsAgent {
+ public:
+  ForwardProcessStatsAgent();
+  ~ForwardProcessStatsAgent() override;
+
+  protocol::ProcessResourceUsage GetResourceUsage() override;
+
+  void OnProcessStats(const protocol::ProcessResourceUsage& usage);
+
+ private:
+  base::Lock lock_;
+  protocol::ProcessResourceUsage usage_;
+};
+
+}  // namespace host
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_FORWARD_PROCESS_STATS_AGENT_H_