Revert of Revert "Remove CpuMonitor and related, unused, code." (patchset #1 id:1 of https://codereview.webrtc.org/1287913004/ )

Reason for revert:
(retrying with my webrtc account...)
The reason for reverting is: Re-landing the change that removes the CpuMonitor class after having fixed the build issue in Chromium..

Original issue's description:
> Revert "Remove CpuMonitor and related, unused, code."
>
> This reverts commit 1a24012680f25440aa1d117373df2af14cdc2fc1.
>
> TBR=tommi@webrtc.org,pthatcher@webrtc.org
> BUG=
>
> This breaks
> http://build.chromium.org/p/chromium.webrtc.fyi/builders/Linux/builds/20148/steps/compile/logs/stdio
>
> Committed: https://chromium.googlesource.com/external/webrtc/+/a472e968c95fb14e63ec42f453551d0967573ea8

TBR=pthatcher@webrtc.org,guoweis@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.webrtc.org/1290033005

Cr-Commit-Position: refs/heads/master@{#9733}
diff --git a/talk/media/webrtc/webrtcvideoengine2.h b/talk/media/webrtc/webrtcvideoengine2.h
index 9d04526..a49f14a 100644
--- a/talk/media/webrtc/webrtcvideoengine2.h
+++ b/talk/media/webrtc/webrtcvideoengine2.h
@@ -36,7 +36,6 @@
 #include "talk/media/webrtc/webrtcvideochannelfactory.h"
 #include "talk/media/webrtc/webrtcvideodecoderfactory.h"
 #include "talk/media/webrtc/webrtcvideoencoderfactory.h"
-#include "webrtc/base/cpumonitor.h"
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/thread_annotations.h"
@@ -54,7 +53,6 @@
 }
 
 namespace rtc {
-class CpuMonitor;
 class Thread;
 }  // namespace rtc
 
diff --git a/webrtc/base/BUILD.gn b/webrtc/base/BUILD.gn
index a587b71..c91869c 100644
--- a/webrtc/base/BUILD.gn
+++ b/webrtc/base/BUILD.gn
@@ -217,8 +217,6 @@
     "basicdefs.h",
     "common.cc",
     "common.h",
-    "cpumonitor.cc",
-    "cpumonitor.h",
     "crc32.cc",
     "crc32.h",
     "cryptstring.cc",
diff --git a/webrtc/base/base.gyp b/webrtc/base/base.gyp
index de2c92f..a5a140f 100644
--- a/webrtc/base/base.gyp
+++ b/webrtc/base/base.gyp
@@ -141,8 +141,6 @@
         'callback.h',
         'common.cc',
         'common.h',
-        'cpumonitor.cc',
-        'cpumonitor.h',
         'crc32.cc',
         'crc32.h',
         'cryptstring.cc',
diff --git a/webrtc/base/base_tests.gyp b/webrtc/base/base_tests.gyp
index 6077c2f..ec2ded0 100644
--- a/webrtc/base/base_tests.gyp
+++ b/webrtc/base/base_tests.gyp
@@ -15,7 +15,6 @@
         'unittest_main.cc',
         # Also use this as a convenient dumping ground for misc files that are
         # included by multiple targets below.
-        'fakecpumonitor.h',
         'fakenetwork.h',
         'fakesslidentity.h',
         'faketaskrunner.h',
@@ -58,7 +57,6 @@
           'bytebuffer_unittest.cc',
           'byteorder_unittest.cc',
           'callback_unittest.cc',
-          'cpumonitor_unittest.cc',
           'crc32_unittest.cc',
           'criticalsection_unittest.cc',
           'event_tracer_unittest.cc',
diff --git a/webrtc/base/cpumonitor.cc b/webrtc/base/cpumonitor.cc
deleted file mode 100644
index c881b48..0000000
--- a/webrtc/base/cpumonitor.cc
+++ /dev/null
@@ -1,423 +0,0 @@
-/*
- *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include "webrtc/base/cpumonitor.h"
-
-#include <string>
-
-#include "webrtc/base/common.h"
-#include "webrtc/base/logging.h"
-#include "webrtc/base/scoped_ptr.h"
-#include "webrtc/base/systeminfo.h"
-#include "webrtc/base/thread.h"
-#include "webrtc/base/timeutils.h"
-
-#if defined(WEBRTC_WIN)
-#include "webrtc/base/win32.h"
-#include <winternl.h>
-#endif
-
-#if defined(WEBRTC_POSIX)
-#include <sys/time.h>
-#endif
-
-#if defined(WEBRTC_MAC)
-#include <mach/mach_host.h>
-#include <mach/mach_init.h>
-#include <mach/mach_port.h>
-#include <mach/host_info.h>
-#include <mach/task.h>
-#endif  // defined(WEBRTC_MAC)
-
-#if defined(WEBRTC_LINUX)
-#include <sys/resource.h>
-#include <errno.h>
-#include <stdio.h>
-#include "webrtc/base/fileutils.h"
-#include "webrtc/base/pathutils.h"
-#endif // defined(WEBRTC_LINUX)
-
-#if defined(WEBRTC_MAC)
-static uint64 TimeValueTToInt64(const time_value_t &time_value) {
-  return rtc::kNumMicrosecsPerSec * time_value.seconds +
-      time_value.microseconds;
-}
-#endif  // defined(WEBRTC_MAC)
-
-// How CpuSampler works
-// When threads switch, the time they spent is accumulated to system counters.
-// The time can be treated as user, kernel or idle.
-// user time is applications.
-// kernel time is the OS, including the thread switching code itself.
-//   typically kernel time indicates IO.
-// idle time is a process that wastes time when nothing is ready to run.
-//
-// User time is broken down by process (application).  One of the applications
-// is the current process.  When you add up all application times, this is
-// system time.  If only your application is running, system time should be the
-// same as process time.
-//
-// All cores contribute to these accumulators.  A dual core process is able to
-// process twice as many cycles as a single core.  The actual code efficiency
-// may be worse, due to contention, but the available cycles is exactly twice
-// as many, and the cpu load will reflect the efficiency.  Hyperthreads behave
-// the same way.  The load will reflect 200%, but the actual amount of work
-// completed will be much less than a true dual core.
-//
-// Total available performance is the sum of all accumulators.
-// If you tracked this for 1 second, it would essentially give you the clock
-// rate - number of cycles per second.
-// Speed step / Turbo Boost is not considered, so infact more processing time
-// may be available.
-
-namespace rtc {
-
-// Note Tests on Windows show 600 ms is minimum stable interval for Windows 7.
-static const int32 kDefaultInterval = 950;  // Slightly under 1 second.
-
-CpuSampler::CpuSampler()
-    : min_load_interval_(kDefaultInterval)
-#if defined(WEBRTC_WIN)
-      , get_system_times_(NULL),
-      nt_query_system_information_(NULL),
-      force_fallback_(false)
-#endif
-    {
-}
-
-CpuSampler::~CpuSampler() {
-}
-
-// Set minimum interval in ms between computing new load values. Default 950.
-void CpuSampler::set_load_interval(int min_load_interval) {
-  min_load_interval_ = min_load_interval;
-}
-
-bool CpuSampler::Init() {
-  sysinfo_.reset(new SystemInfo);
-  cpus_ = sysinfo_->GetMaxCpus();
-  if (cpus_ == 0) {
-    return false;
-  }
-#if defined(WEBRTC_WIN)
-  // Note that GetSystemTimes is available in Windows XP SP1 or later.
-  // http://msdn.microsoft.com/en-us/library/ms724400.aspx
-  // NtQuerySystemInformation is used as a fallback.
-  if (!force_fallback_) {
-    get_system_times_ = GetProcAddress(GetModuleHandle(L"kernel32.dll"),
-        "GetSystemTimes");
-  }
-  nt_query_system_information_ = GetProcAddress(GetModuleHandle(L"ntdll.dll"),
-      "NtQuerySystemInformation");
-  if ((get_system_times_ == NULL) && (nt_query_system_information_ == NULL)) {
-    return false;
-  }
-#endif
-#if defined(WEBRTC_LINUX)
-  Pathname sname("/proc/stat");
-  sfile_.reset(Filesystem::OpenFile(sname, "rb"));
-  if (!sfile_) {
-    LOG_ERR(LS_ERROR) << "open proc/stat failed:";
-    return false;
-  }
-  if (!sfile_->DisableBuffering()) {
-    LOG_ERR(LS_ERROR) << "could not disable buffering for proc/stat";
-    return false;
-  }
-#endif // defined(WEBRTC_LINUX)
-  GetProcessLoad();  // Initialize values.
-  GetSystemLoad();
-  // Help next user call return valid data by recomputing load.
-  process_.prev_load_time_ = 0u;
-  system_.prev_load_time_ = 0u;
-  return true;
-}
-
-float CpuSampler::UpdateCpuLoad(uint64 current_total_times,
-                                uint64 current_cpu_times,
-                                uint64 *prev_total_times,
-                                uint64 *prev_cpu_times) {
-  float result = 0.f;
-  if (current_total_times < *prev_total_times ||
-      current_cpu_times < *prev_cpu_times) {
-    LOG(LS_ERROR) << "Inconsistent time values are passed. ignored";
-  } else {
-    const uint64 cpu_diff = current_cpu_times - *prev_cpu_times;
-    const uint64 total_diff = current_total_times - *prev_total_times;
-    result = (total_diff == 0ULL ? 0.f :
-              static_cast<float>(1.0f * cpu_diff / total_diff));
-    if (result > static_cast<float>(cpus_)) {
-      result = static_cast<float>(cpus_);
-    }
-    *prev_total_times = current_total_times;
-    *prev_cpu_times = current_cpu_times;
-  }
-  return result;
-}
-
-float CpuSampler::GetSystemLoad() {
-  uint32 timenow = Time();
-  int elapsed = static_cast<int>(TimeDiff(timenow, system_.prev_load_time_));
-  if (min_load_interval_ != 0 && system_.prev_load_time_ != 0u &&
-      elapsed < min_load_interval_) {
-    return system_.prev_load_;
-  }
-#if defined(WEBRTC_WIN)
-  uint64 total_times, cpu_times;
-
-  typedef BOOL (_stdcall *GST_PROC)(LPFILETIME, LPFILETIME, LPFILETIME);
-  typedef NTSTATUS (WINAPI *QSI_PROC)(SYSTEM_INFORMATION_CLASS,
-      PVOID, ULONG, PULONG);
-
-  GST_PROC get_system_times = reinterpret_cast<GST_PROC>(get_system_times_);
-  QSI_PROC nt_query_system_information = reinterpret_cast<QSI_PROC>(
-      nt_query_system_information_);
-
-  if (get_system_times) {
-    FILETIME idle_time, kernel_time, user_time;
-    if (!get_system_times(&idle_time, &kernel_time, &user_time)) {
-      LOG(LS_ERROR) << "::GetSystemTimes() failed: " << ::GetLastError();
-      return 0.f;
-    }
-    // kernel_time includes Kernel idle time, so no need to
-    // include cpu_time as total_times
-    total_times = ToUInt64(kernel_time) + ToUInt64(user_time);
-    cpu_times = total_times - ToUInt64(idle_time);
-
-  } else {
-    if (nt_query_system_information) {
-      ULONG returned_length = 0;
-      scoped_ptr<SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[]> processor_info(
-          new SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[cpus_]);
-      nt_query_system_information(
-          ::SystemProcessorPerformanceInformation,
-          reinterpret_cast<void*>(processor_info.get()),
-          cpus_ * sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION),
-          &returned_length);
-
-      if (returned_length !=
-          (cpus_ * sizeof(SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION))) {
-        LOG(LS_ERROR) << "NtQuerySystemInformation has unexpected size";
-        return 0.f;
-      }
-
-      uint64 current_idle = 0;
-      uint64 current_kernel = 0;
-      uint64 current_user = 0;
-      for (int ix = 0; ix < cpus_; ++ix) {
-        current_idle += processor_info[ix].IdleTime.QuadPart;
-        current_kernel += processor_info[ix].UserTime.QuadPart;
-        current_user += processor_info[ix].KernelTime.QuadPart;
-      }
-      total_times = current_kernel + current_user;
-      cpu_times = total_times - current_idle;
-    } else {
-      return 0.f;
-    }
-  }
-#endif  // WEBRTC_WIN 
-
-#if defined(WEBRTC_MAC)
-  mach_port_t mach_host = mach_host_self();
-  host_cpu_load_info_data_t cpu_info;
-  mach_msg_type_number_t info_count = HOST_CPU_LOAD_INFO_COUNT;
-  kern_return_t kr = host_statistics(mach_host, HOST_CPU_LOAD_INFO,
-                                     reinterpret_cast<host_info_t>(&cpu_info),
-                                     &info_count);
-  mach_port_deallocate(mach_task_self(), mach_host);
-  if (KERN_SUCCESS != kr) {
-    LOG(LS_ERROR) << "::host_statistics() failed";
-    return 0.f;
-  }
-
-  const uint64 cpu_times = cpu_info.cpu_ticks[CPU_STATE_NICE] +
-      cpu_info.cpu_ticks[CPU_STATE_SYSTEM] +
-      cpu_info.cpu_ticks[CPU_STATE_USER];
-  const uint64 total_times = cpu_times + cpu_info.cpu_ticks[CPU_STATE_IDLE];
-#endif  // defined(WEBRTC_MAC)
-
-#if defined(WEBRTC_LINUX)
-  if (!sfile_) {
-    LOG(LS_ERROR) << "Invalid handle for proc/stat";
-    return 0.f;
-  }
-  std::string statbuf;
-  sfile_->SetPosition(0);
-  if (!sfile_->ReadLine(&statbuf)) {
-    LOG_ERR(LS_ERROR) << "Could not read proc/stat file";
-    return 0.f;
-  }
-
-  unsigned long long user;
-  unsigned long long nice;
-  unsigned long long system;
-  unsigned long long idle;
-  if (sscanf(statbuf.c_str(), "cpu %Lu %Lu %Lu %Lu",
-             &user, &nice,
-             &system, &idle) != 4) {
-    LOG_ERR(LS_ERROR) << "Could not parse cpu info";
-    return 0.f;
-  }
-  const uint64 cpu_times = nice + system + user;
-  const uint64 total_times = cpu_times + idle;
-#endif  // defined(WEBRTC_LINUX)
-
-#if defined(__native_client__)
-  // TODO(ryanpetrie): Implement this via PPAPI when it's available.
-  const uint64 cpu_times = 0;
-  const uint64 total_times = 0;
-#endif  // defined(__native_client__)
-
-  system_.prev_load_time_ = timenow;
-  system_.prev_load_ = UpdateCpuLoad(total_times,
-                                     cpu_times * cpus_,
-                                     &system_.prev_total_times_,
-                                     &system_.prev_cpu_times_);
-  return system_.prev_load_;
-}
-
-float CpuSampler::GetProcessLoad() {
-  uint32 timenow = Time();
-  int elapsed = static_cast<int>(TimeDiff(timenow, process_.prev_load_time_));
-  if (min_load_interval_ != 0 && process_.prev_load_time_ != 0u &&
-      elapsed < min_load_interval_) {
-    return process_.prev_load_;
-  }
-#if defined(WEBRTC_WIN)
-  FILETIME current_file_time;
-  ::GetSystemTimeAsFileTime(&current_file_time);
-
-  FILETIME create_time, exit_time, kernel_time, user_time;
-  if (!::GetProcessTimes(::GetCurrentProcess(),
-                         &create_time, &exit_time, &kernel_time, &user_time)) {
-    LOG(LS_ERROR) << "::GetProcessTimes() failed: " << ::GetLastError();
-    return 0.f;
-  }
-
-  const uint64 total_times =
-      ToUInt64(current_file_time) - ToUInt64(create_time);
-  const uint64 cpu_times =
-      (ToUInt64(kernel_time) + ToUInt64(user_time));
-#endif  // WEBRTC_WIN 
-
-#if defined(WEBRTC_POSIX)
-  // Common to both OSX and Linux.
-  struct timeval tv;
-  gettimeofday(&tv, NULL);
-  const uint64 total_times = tv.tv_sec * kNumMicrosecsPerSec + tv.tv_usec;
-#endif
-
-#if defined(WEBRTC_MAC)
-  // Get live thread usage.
-  task_thread_times_info task_times_info;
-  mach_msg_type_number_t info_count = TASK_THREAD_TIMES_INFO_COUNT;
-
-  if (KERN_SUCCESS != task_info(mach_task_self(), TASK_THREAD_TIMES_INFO,
-                                reinterpret_cast<task_info_t>(&task_times_info),
-                                &info_count)) {
-    LOG(LS_ERROR) << "::task_info(TASK_THREAD_TIMES_INFO) failed";
-    return 0.f;
-  }
-
-  // Get terminated thread usage.
-  task_basic_info task_term_info;
-  info_count = TASK_BASIC_INFO_COUNT;
-  if (KERN_SUCCESS != task_info(mach_task_self(), TASK_BASIC_INFO,
-                                reinterpret_cast<task_info_t>(&task_term_info),
-                                &info_count)) {
-    LOG(LS_ERROR) << "::task_info(TASK_BASIC_INFO) failed";
-    return 0.f;
-  }
-
-  const uint64 cpu_times = (TimeValueTToInt64(task_times_info.user_time) +
-      TimeValueTToInt64(task_times_info.system_time) +
-      TimeValueTToInt64(task_term_info.user_time) +
-      TimeValueTToInt64(task_term_info.system_time));
-#endif  // defined(WEBRTC_MAC)
-
-#if defined(WEBRTC_LINUX)
-  rusage usage;
-  if (getrusage(RUSAGE_SELF, &usage) < 0) {
-    LOG_ERR(LS_ERROR) << "getrusage failed";
-    return 0.f;
-  }
-
-  const uint64 cpu_times =
-      (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) * kNumMicrosecsPerSec +
-      usage.ru_utime.tv_usec + usage.ru_stime.tv_usec;
-#endif  // defined(WEBRTC_LINUX)
-
-#if defined(__native_client__)
-  // TODO(ryanpetrie): Implement this via PPAPI when it's available.
-  const uint64 cpu_times = 0;
-#endif  // defined(__native_client__)
-
-  process_.prev_load_time_ = timenow;
-  process_.prev_load_ = UpdateCpuLoad(total_times,
-                                     cpu_times,
-                                     &process_.prev_total_times_,
-                                     &process_.prev_cpu_times_);
-  return process_.prev_load_;
-}
-
-int CpuSampler::GetMaxCpus() const {
-  return cpus_;
-}
-
-int CpuSampler::GetCurrentCpus() {
-  return sysinfo_->GetCurCpus();
-}
-
-///////////////////////////////////////////////////////////////////
-// Implementation of class CpuMonitor.
-CpuMonitor::CpuMonitor(Thread* thread)
-    : monitor_thread_(thread) {
-}
-
-CpuMonitor::~CpuMonitor() {
-  Stop();
-}
-
-void CpuMonitor::set_thread(Thread* thread) {
-  ASSERT(monitor_thread_ == NULL || monitor_thread_ == thread);
-  monitor_thread_ = thread;
-}
-
-bool CpuMonitor::Start(int period_ms) {
-  if (!monitor_thread_  || !sampler_.Init()) return false;
-
-  monitor_thread_->SignalQueueDestroyed.connect(
-       this, &CpuMonitor::OnMessageQueueDestroyed);
-
-  period_ms_ = period_ms;
-  monitor_thread_->PostDelayed(period_ms_, this);
-
-  return true;
-}
-
-void CpuMonitor::Stop() {
-  if (monitor_thread_) {
-    monitor_thread_->Clear(this);
-  }
-}
-
-void CpuMonitor::OnMessage(Message* msg) {
-  int max_cpus = sampler_.GetMaxCpus();
-  int current_cpus = sampler_.GetCurrentCpus();
-  float process_load = sampler_.GetProcessLoad();
-  float system_load = sampler_.GetSystemLoad();
-  SignalUpdate(current_cpus, max_cpus, process_load, system_load);
-
-  if (monitor_thread_) {
-    monitor_thread_->PostDelayed(period_ms_, this);
-  }
-}
-
-}  // namespace rtc
diff --git a/webrtc/base/cpumonitor.h b/webrtc/base/cpumonitor.h
deleted file mode 100644
index e82ae69..0000000
--- a/webrtc/base/cpumonitor.h
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_BASE_CPUMONITOR_H_
-#define WEBRTC_BASE_CPUMONITOR_H_
-
-#include "webrtc/base/basictypes.h"
-#include "webrtc/base/messagehandler.h"
-#include "webrtc/base/scoped_ptr.h"
-#include "webrtc/base/sigslot.h"
-#if defined(WEBRTC_LINUX)
-#include "webrtc/base/stream.h"
-#endif // defined(WEBRTC_LINUX)
-
-namespace rtc {
-class Thread;
-class SystemInfo;
-
-struct CpuStats {
-  CpuStats()
-      : prev_total_times_(0),
-        prev_cpu_times_(0),
-        prev_load_(0.f),
-        prev_load_time_(0u) {
-  }
-
-  uint64 prev_total_times_;
-  uint64 prev_cpu_times_;
-  float prev_load_;  // Previous load value.
-  uint32 prev_load_time_;  // Time previous load value was taken.
-};
-
-// CpuSampler samples the process and system load.
-class CpuSampler {
- public:
-  CpuSampler();
-  ~CpuSampler();
-
-  // Initialize CpuSampler.  Returns true if successful.
-  bool Init();
-
-  // Set minimum interval in ms between computing new load values.
-  // Default 950 ms.  Set to 0 to disable interval.
-  void set_load_interval(int min_load_interval);
-
-  // Return CPU load of current process as a float from 0 to 1.
-  float GetProcessLoad();
-
-  // Return CPU load of current process as a float from 0 to 1.
-  float GetSystemLoad();
-
-  // Return number of cpus. Includes hyperthreads.
-  int GetMaxCpus() const;
-
-  // Return current number of cpus available to this process.
-  int GetCurrentCpus();
-
-  // For testing. Allows forcing of fallback to using NTDLL functions.
-  void set_force_fallback(bool fallback) {
-#if defined(WEBRTC_WIN)
-    force_fallback_ = fallback;
-#endif
-  }
-
- private:
-  float UpdateCpuLoad(uint64 current_total_times,
-                      uint64 current_cpu_times,
-                      uint64 *prev_total_times,
-                      uint64 *prev_cpu_times);
-  CpuStats process_;
-  CpuStats system_;
-  int cpus_;
-  int min_load_interval_;  // Minimum time between computing new load.
-  scoped_ptr<SystemInfo> sysinfo_;
-#if defined(WEBRTC_WIN)
-  void* get_system_times_;
-  void* nt_query_system_information_;
-  bool force_fallback_;
-#endif
-#if defined(WEBRTC_LINUX)
-  // File for reading /proc/stat
-  scoped_ptr<FileStream> sfile_;
-#endif // defined(WEBRTC_LINUX)
-};
-
-// CpuMonitor samples and signals the CPU load periodically.
-class CpuMonitor
-    : public rtc::MessageHandler, public sigslot::has_slots<> {
- public:
-  explicit CpuMonitor(Thread* thread);
-  ~CpuMonitor() override;
-  void set_thread(Thread* thread);
-
-  bool Start(int period_ms);
-  void Stop();
-  // Signal parameters are current cpus, max cpus, process load and system load.
-  sigslot::signal4<int, int, float, float> SignalUpdate;
-
- protected:
-  // Override virtual method of parent MessageHandler.
-  void OnMessage(rtc::Message* msg) override;
-  // Clear the monitor thread and stop sending it messages if the thread goes
-  // away before our lifetime.
-  void OnMessageQueueDestroyed() { monitor_thread_ = NULL; }
-
- private:
-  Thread* monitor_thread_;
-  CpuSampler sampler_;
-  int period_ms_;
-
-  DISALLOW_COPY_AND_ASSIGN(CpuMonitor);
-};
-
-}  // namespace rtc
-
-#endif  // WEBRTC_BASE_CPUMONITOR_H_
diff --git a/webrtc/base/fakecpumonitor.h b/webrtc/base/fakecpumonitor.h
deleted file mode 100644
index c6ea0f2..0000000
--- a/webrtc/base/fakecpumonitor.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#ifndef WEBRTC_BASE_FAKECPUMONITOR_H_
-#define WEBRTC_BASE_FAKECPUMONITOR_H_
-
-#include "webrtc/base/cpumonitor.h"
-
-namespace rtc {
-
-class FakeCpuMonitor : public rtc::CpuMonitor {
- public:
-  explicit FakeCpuMonitor(Thread* thread)
-      : CpuMonitor(thread) {
-  }
-  ~FakeCpuMonitor() {
-  }
-
-  virtual void OnMessage(rtc::Message* msg) {
-  }
-};
-
-}  // namespace rtc
-
-#endif  // WEBRTC_BASE_FAKECPUMONITOR_H_