Revert of [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/threading/thread_checker.h"
-#include "remoting/host/process_stats_agent.h"
-#include "remoting/proto/process_stats.pb.h"
-
-namespace remoting {
-
-// ProcessStatsAgent implementation that returns stats passed to
-// OnProcessStats(). Used to collect stats from processes other than the current
-// one. All public functions, not including constructor and destructor, of the
-// object of ForwardProcessStatsAgent are expected to be called in a same
-// thread.
-class ForwardProcessStatsAgent final : public ProcessStatsAgent {
- public:
-  ForwardProcessStatsAgent();
-  ~ForwardProcessStatsAgent() override;
-
-  void OnProcessStats(const protocol::ProcessResourceUsage& usage);
-
-  // ProcessStatsAgent implementation.
-  protocol::ProcessResourceUsage GetResourceUsage() override;
-
- private:
-  base::ThreadChecker thread_checker_;
-  protocol::ProcessResourceUsage usage_;
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_HOST_FORWARD_PROCESS_STATS_AGENT_H_