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

remoting/protocol/process_stats_stub.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_PROTOCOL_PROCESS_STATS_STUB_H_
-#define REMOTING_PROTOCOL_PROCESS_STATS_STUB_H_
-
-#include "remoting/proto/process_stats.pb.h"
-
-namespace remoting {
-namespace protocol {
-
-// An interface to receive process statistic data.
-class ProcessStatsStub {
- public:
-  ProcessStatsStub() = default;
-  virtual ~ProcessStatsStub() = default;
-
-  virtual void OnProcessStats(
-      const protocol::AggregatedProcessResourceUsage& usage) = 0;
-};
-
-}  // namespace protocol
-}  // namespace remoting
-
-#endif  // REMOTING_PROTOCOL_PROCESS_STATS_STUB_H_