Shift PowerMonitor to non static

Bug: 346931324
Change-Id: I80fab35a422083c5a9db1d9ee4a2ccd34e11d32f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5806403
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Owners-Override: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1350494}

ash/login/ui/lock_screen_media_view.cc

@@ -79,8 +79,8 @@ LockScreenMediaView::LockScreenMediaView(
       hide_media_view_callback_(hide_media_view_callback) {
   // Observe power events and if created in power suspended state, post
   // OnSuspend() call to run after LockContentsView is initialized.
-  if (base::PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(
+  if (base::PowerMonitor::GetInstance()
-          this)) {
+          ->AddPowerSuspendObserverAndReturnSuspendedState(this)) {
     base::SingleThreadTaskRunner::GetCurrentDefault()->PostTask(
         FROM_HERE, base::BindOnce(&LockScreenMediaView::OnSuspend,
                                   weak_ptr_factory_.GetWeakPtr()));
@@ -137,7 +137,7 @@ LockScreenMediaView::LockScreenMediaView(
 }
 
 LockScreenMediaView::~LockScreenMediaView() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 ///////////////////////////////////////////////////////////////////////////////

base/power_monitor/power_monitor.cc

@@ -16,62 +16,50 @@ namespace base {
 
 void PowerMonitor::Initialize(std::unique_ptr<PowerMonitorSource> source) {
   DCHECK(!IsInitialized());
-  PowerMonitor* power_monitor = GetInstance();
+  source_ = std::move(source);
-  power_monitor->source_ = std::move(source);
 
   // When a power source is associated with the power monitor, ensure the
   // initial state is propagated to observers, if needed.
-  PowerMonitor::NotifyPowerStateChange(
+  NotifyPowerStateChange(Source()->GetBatteryPowerStatus());
-      PowerMonitor::Source()->GetBatteryPowerStatus());
 
-  PowerMonitor::PowerMonitor::NotifyThermalStateChange(
+  NotifyThermalStateChange(Source()->GetCurrentThermalState());
-      PowerMonitor::Source()->GetCurrentThermalState());
 
-  PowerMonitor::PowerMonitor::NotifySpeedLimitChange(
+  NotifySpeedLimitChange(Source()->GetInitialSpeedLimit());
-      PowerMonitor::Source()->GetInitialSpeedLimit());
 }
 
-bool PowerMonitor::IsInitialized() {
+bool PowerMonitor::IsInitialized() const {
-  return GetInstance()->source_.get() != nullptr;
+  return source_ != nullptr;
 }
 
-// static
 void PowerMonitor::AddPowerSuspendObserver(PowerSuspendObserver* obs) {
-  GetInstance()->power_suspend_observers_->AddObserver(obs);
+  power_suspend_observers_->AddObserver(obs);
 }
 
-// static
 void PowerMonitor::RemovePowerSuspendObserver(PowerSuspendObserver* obs) {
-  GetInstance()->power_suspend_observers_->RemoveObserver(obs);
+  power_suspend_observers_->RemoveObserver(obs);
 }
 
-// static
 void PowerMonitor::AddPowerStateObserver(PowerStateObserver* obs) {
-  GetInstance()->power_state_observers_->AddObserver(obs);
+  power_state_observers_->AddObserver(obs);
 }
 
-// static
 void PowerMonitor::RemovePowerStateObserver(PowerStateObserver* obs) {
-  GetInstance()->power_state_observers_->RemoveObserver(obs);
+  power_state_observers_->RemoveObserver(obs);
 }
 
-// static
 void PowerMonitor::AddPowerThermalObserver(PowerThermalObserver* obs) {
-  GetInstance()->thermal_state_observers_->AddObserver(obs);
+  thermal_state_observers_->AddObserver(obs);
 }
 
-// static
 void PowerMonitor::RemovePowerThermalObserver(PowerThermalObserver* obs) {
-  GetInstance()->thermal_state_observers_->RemoveObserver(obs);
+  thermal_state_observers_->RemoveObserver(obs);
 }
 
-// static
 bool PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(
     PowerSuspendObserver* obs) {
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(is_system_suspended_lock_);
-  AutoLock auto_lock(power_monitor->is_system_suspended_lock_);
+  power_suspend_observers_->AddObserver(obs);
-  power_monitor->power_suspend_observers_->AddObserver(obs);
+  return is_system_suspended_;
-  return power_monitor->is_system_suspended_;
 }
 
 // static
@@ -84,84 +72,79 @@ bool PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(
 PowerStateObserver::BatteryPowerStatus
 PowerMonitor::AddPowerStateObserverAndReturnBatteryPowerStatus(
     PowerStateObserver* obs) {
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(battery_power_status_lock_);
-  AutoLock auto_lock(power_monitor->battery_power_status_lock_);
+  power_state_observers_->AddObserver(obs);
-  power_monitor->power_state_observers_->AddObserver(obs);
+  return battery_power_status_;
-  return power_monitor->battery_power_status_;
 }
 
 // static
 PowerThermalObserver::DeviceThermalState
 PowerMonitor::AddPowerStateObserverAndReturnPowerThermalState(
     PowerThermalObserver* obs) {
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(power_thermal_state_lock_);
-  AutoLock auto_lock(power_monitor->power_thermal_state_lock_);
+  thermal_state_observers_->AddObserver(obs);
-  power_monitor->thermal_state_observers_->AddObserver(obs);
+  return power_thermal_state_;
-  return power_monitor->power_thermal_state_;
 }
 
-PowerMonitorSource* PowerMonitor::Source() {
+const PowerMonitorSource* PowerMonitor::Source() const {
-  return GetInstance()->source_.get();
+  return source_.get();
 }
 
-bool PowerMonitor::IsOnBatteryPower() {
+bool PowerMonitor::IsOnBatteryPower() const {
   DCHECK(IsInitialized());
   return GetBatteryPowerStatus() ==
          PowerStateObserver::BatteryPowerStatus::kBatteryPower;
 }
 
-PowerStateObserver::BatteryPowerStatus PowerMonitor::GetBatteryPowerStatus() {
+PowerStateObserver::BatteryPowerStatus PowerMonitor::GetBatteryPowerStatus()
+    const {
   DCHECK(IsInitialized());
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(battery_power_status_lock_);
-  AutoLock auto_lock(power_monitor->battery_power_status_lock_);
+  return battery_power_status_;
-  return power_monitor->battery_power_status_;
 }
 
-TimeTicks PowerMonitor::GetLastSystemResumeTime() {
+TimeTicks PowerMonitor::GetLastSystemResumeTime() const {
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(is_system_suspended_lock_);
-  AutoLock auto_lock(power_monitor->is_system_suspended_lock_);
+  return last_system_resume_time_;
-  return power_monitor->last_system_resume_time_;
 }
 
 void PowerMonitor::ShutdownForTesting() {
-  GetInstance()->source_ = nullptr;
+  source_ = nullptr;
 
-  PowerMonitor* power_monitor = GetInstance();
   {
-    AutoLock auto_lock(power_monitor->is_system_suspended_lock_);
+    AutoLock auto_lock(is_system_suspended_lock_);
-    power_monitor->is_system_suspended_ = false;
+    is_system_suspended_ = false;
-    power_monitor->last_system_resume_time_ = TimeTicks();
+    last_system_resume_time_ = TimeTicks();
   }
   {
-    AutoLock auto_lock(power_monitor->battery_power_status_lock_);
+    AutoLock auto_lock(battery_power_status_lock_);
-    power_monitor->battery_power_status_ =
+    battery_power_status_ =
         PowerStateObserver::BatteryPowerStatus::kExternalPower;
   }
   {
-    AutoLock auto_lock(power_monitor->power_thermal_state_lock_);
+    AutoLock auto_lock(power_thermal_state_lock_);
-    power_monitor->power_thermal_state_ =
+    power_thermal_state_ = PowerThermalObserver::DeviceThermalState::kUnknown;
-        PowerThermalObserver::DeviceThermalState::kUnknown;
   }
 }
 
 // static
-PowerThermalObserver::DeviceThermalState
+PowerThermalObserver::DeviceThermalState PowerMonitor::GetCurrentThermalState()
-PowerMonitor::GetCurrentThermalState() {
+    const {
   DCHECK(IsInitialized());
-  return GetInstance()->source_->GetCurrentThermalState();
+  return source_->GetCurrentThermalState();
 }
 
 // static
 void PowerMonitor::SetCurrentThermalState(
     PowerThermalObserver::DeviceThermalState state) {
   DCHECK(IsInitialized());
-  GetInstance()->source_->SetCurrentThermalState(state);
+  source_->SetCurrentThermalState(state);
 }
 
 #if BUILDFLAG(IS_ANDROID)
-int PowerMonitor::GetRemainingBatteryCapacity() {
+int PowerMonitor::GetRemainingBatteryCapacity() const {
   DCHECK(IsInitialized());
-  return PowerMonitor::Source()->GetRemainingBatteryCapacity();
+  return Source()->GetRemainingBatteryCapacity();
 }
 #endif  // BUILDFLAG(IS_ANDROID)
 
@@ -188,11 +171,10 @@ void PowerMonitor::NotifyPowerStateChange(
              << " battery";
   }
 
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(battery_power_status_lock_);
-  AutoLock auto_lock(power_monitor->battery_power_status_lock_);
+  if (battery_power_status_ != battery_power_status) {
-  if (power_monitor->battery_power_status_ != battery_power_status) {
+    battery_power_status_ = battery_power_status;
-    power_monitor->battery_power_status_ = battery_power_status;
+    power_state_observers_->Notify(
-    GetInstance()->power_state_observers_->Notify(
         FROM_HERE, &PowerStateObserver::OnBatteryPowerStatusChange,
         battery_power_status);
   }
@@ -204,13 +186,12 @@ void PowerMonitor::NotifySuspend() {
                        TRACE_EVENT_SCOPE_PROCESS);
   DVLOG(1) << "Power Suspending";
 
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(is_system_suspended_lock_);
-  AutoLock auto_lock(power_monitor->is_system_suspended_lock_);
+  if (!is_system_suspended_) {
-  if (!power_monitor->is_system_suspended_) {
+    is_system_suspended_ = true;
-    power_monitor->is_system_suspended_ = true;
+    last_system_resume_time_ = TimeTicks::Max();
-    power_monitor->last_system_resume_time_ = TimeTicks::Max();
+    power_suspend_observers_->Notify(FROM_HERE,
-    GetInstance()->power_suspend_observers_->Notify(
+                                     &PowerSuspendObserver::OnSuspend);
-        FROM_HERE, &PowerSuspendObserver::OnSuspend);
   }
 }
 
@@ -222,13 +203,12 @@ void PowerMonitor::NotifyResume() {
 
   TimeTicks resume_time = TimeTicks::Now();
 
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(is_system_suspended_lock_);
-  AutoLock auto_lock(power_monitor->is_system_suspended_lock_);
+  if (is_system_suspended_) {
-  if (power_monitor->is_system_suspended_) {
+    is_system_suspended_ = false;
-    power_monitor->is_system_suspended_ = false;
+    last_system_resume_time_ = resume_time;
-    power_monitor->last_system_resume_time_ = resume_time;
+    power_suspend_observers_->Notify(FROM_HERE,
-    GetInstance()->power_suspend_observers_->Notify(
+                                     &PowerSuspendObserver::OnResume);
-        FROM_HERE, &PowerSuspendObserver::OnResume);
   }
 }
 
@@ -238,11 +218,10 @@ void PowerMonitor::NotifyThermalStateChange(
   DVLOG(1) << "ThermalStateChange: "
            << PowerMonitorSource::DeviceThermalStateToString(new_state);
 
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(power_thermal_state_lock_);
-  AutoLock auto_lock(power_monitor->power_thermal_state_lock_);
+  if (power_thermal_state_ != new_state) {
-  if (power_monitor->power_thermal_state_ != new_state) {
+    power_thermal_state_ = new_state;
-    power_monitor->power_thermal_state_ = new_state;
+    thermal_state_observers_->Notify(
-    GetInstance()->thermal_state_observers_->Notify(
         FROM_HERE, &PowerThermalObserver::OnThermalStateChange, new_state);
   }
 }
@@ -251,11 +230,10 @@ void PowerMonitor::NotifySpeedLimitChange(int speed_limit) {
   DCHECK(IsInitialized());
   DVLOG(1) << "SpeedLimitChange: " << speed_limit;
 
-  PowerMonitor* power_monitor = GetInstance();
+  AutoLock auto_lock(power_thermal_state_lock_);
-  AutoLock auto_lock(power_monitor->power_thermal_state_lock_);
+  if (speed_limit_ != speed_limit) {
-  if (power_monitor->speed_limit_ != speed_limit) {
+    speed_limit_ = speed_limit;
-    power_monitor->speed_limit_ = speed_limit;
+    thermal_state_observers_->Notify(
-    GetInstance()->thermal_state_observers_->Notify(
         FROM_HERE, &PowerThermalObserver::OnSpeedLimitChange, speed_limit);
   }
 }

base/power_monitor/power_monitor.h

@@ -26,11 +26,13 @@ class PowerMonitorSource;
 // of test contexts where the PowerMonitor global is never created.
 class BASE_EXPORT PowerMonitor {
  public:
+  static PowerMonitor* GetInstance();
+
   // Initializes global PowerMonitor state. Takes ownership of |source|, which
   // will be leaked on process teardown. May only be called once. Not threadsafe
   // - no other PowerMonitor methods may be called on any thread while calling
   // Initialize(). |source| must not be nullptr.
-  static void Initialize(std::unique_ptr<PowerMonitorSource> source);
+  void Initialize(std::unique_ptr<PowerMonitorSource> source);
 
   PowerMonitor(const PowerMonitor&) = delete;
   PowerMonitor& operator=(const PowerMonitor&) = delete;
@@ -38,7 +40,7 @@ class BASE_EXPORT PowerMonitor {
   // Returns true if Initialize() has been called. Safe to call on any thread,
   // but must not be called while Initialize() or ShutdownForTesting() is being
   // invoked.
-  static bool IsInitialized();
+  bool IsInitialized() const;
 
   // Add and remove an observer.
   // Can be called from any thread. |observer| is notified on the sequence
@@ -47,12 +49,12 @@ class BASE_EXPORT PowerMonitor {
   //
   // It is safe to add observers before the PowerMonitor is initialized. It is
   // safe to remove an observer even if it was not added as an observer.
-  static void AddPowerSuspendObserver(PowerSuspendObserver* observer);
+  void AddPowerSuspendObserver(PowerSuspendObserver* observer);
-  static void RemovePowerSuspendObserver(PowerSuspendObserver* observer);
+  void RemovePowerSuspendObserver(PowerSuspendObserver* observer);
-  static void AddPowerStateObserver(PowerStateObserver* observer);
+  void AddPowerStateObserver(PowerStateObserver* observer);
-  static void RemovePowerStateObserver(PowerStateObserver* observer);
+  void RemovePowerStateObserver(PowerStateObserver* observer);
-  static void AddPowerThermalObserver(PowerThermalObserver* observer);
+  void AddPowerThermalObserver(PowerThermalObserver* observer);
-  static void RemovePowerThermalObserver(PowerThermalObserver* observer);
+  void RemovePowerThermalObserver(PowerThermalObserver* observer);
 
   // Atomically add a PowerSuspendObserver and read the current power suspended
   // state. This variant must be used to avoid race between adding an observer
@@ -61,54 +63,53 @@ class BASE_EXPORT PowerMonitor {
   //    if (PowerMonitor::IsSystemSuspended()) { ... }
   //
   // Returns true if the system is currently suspended.
-  static bool AddPowerSuspendObserverAndReturnSuspendedState(
+  bool AddPowerSuspendObserverAndReturnSuspendedState(
       PowerSuspendObserver* observer);
   // Returns true if the system is on-battery.
-  static bool AddPowerStateObserverAndReturnOnBatteryState(
+  bool AddPowerStateObserverAndReturnOnBatteryState(
       PowerStateObserver* observer);
-  static PowerStateObserver::BatteryPowerStatus
+  PowerStateObserver::BatteryPowerStatus
   AddPowerStateObserverAndReturnBatteryPowerStatus(
       PowerStateObserver* observer);
   // Returns the power thermal state.
-  static PowerThermalObserver::DeviceThermalState
+  PowerThermalObserver::DeviceThermalState
   AddPowerStateObserverAndReturnPowerThermalState(
       PowerThermalObserver* observer);
 
   // Is the computer currently on battery power. May only be called if the
   // PowerMonitor has been initialized.
-  static bool IsOnBatteryPower();
+  bool IsOnBatteryPower() const;
 
   // Returns the current state of the battery power, that can be unknown if the
   // value isn't initialized yet. May only be called if the PowerMonitor has
   // been initialized.
-  static PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus();
+  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() const;
 
   // Returns the time of the last system resume. If no system suspend/resume was
   // observed, returns an empty time. If the system is currently suspended,
   // returns TimeTicks::Max().
-  static TimeTicks GetLastSystemResumeTime();
+  TimeTicks GetLastSystemResumeTime() const;
 
   // Read the current DeviceThermalState if known. Can be called on any thread.
   // May only be called if the PowerMonitor has been initialized.
-  static PowerThermalObserver::DeviceThermalState GetCurrentThermalState();
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() const;
 
   // Update the result of thermal state.
-  static void SetCurrentThermalState(
+  void SetCurrentThermalState(PowerThermalObserver::DeviceThermalState state);
-      PowerThermalObserver::DeviceThermalState state);
 
 #if BUILDFLAG(IS_ANDROID)
   // Read and return the current remaining battery capacity (microampere-hours).
   // Only supported with a device power source (i.e. not in child processes in
   // Chrome) and on devices with Android >= Lollipop as well as a power supply
   // that supports this counter. Returns 0 if unsupported.
-  static int GetRemainingBatteryCapacity();
+  int GetRemainingBatteryCapacity() const;
 #endif  // BUILDFLAG(IS_ANDROID)
 
   // Uninitializes the PowerMonitor. Should be called at the end of any unit
   // test that mocks out the PowerMonitor, to avoid affecting subsequent tests.
   // There must be no live observers when invoked. Safe to call even if the
   // PowerMonitor hasn't been initialized.
-  static void ShutdownForTesting();
+  void ShutdownForTesting();
 
  private:
   friend class PowerMonitorSource;
@@ -117,27 +118,25 @@ class BASE_EXPORT PowerMonitor {
   PowerMonitor();
   ~PowerMonitor();
 
-  static PowerMonitorSource* Source();
+  const PowerMonitorSource* Source() const;
 
-  static void NotifyPowerStateChange(bool on_battery_power);
+  void NotifyPowerStateChange(bool on_battery_power);
-  static void NotifyPowerStateChange(
+  void NotifyPowerStateChange(
       PowerStateObserver::BatteryPowerStatus battery_power_status);
-  static void NotifySuspend();
+  void NotifySuspend();
-  static void NotifyResume();
+  void NotifyResume();
-  static void NotifyThermalStateChange(
+  void NotifyThermalStateChange(
       PowerThermalObserver::DeviceThermalState new_state);
-  static void NotifySpeedLimitChange(int speed_limit);
+  void NotifySpeedLimitChange(int speed_limit);
-
-  static PowerMonitor* GetInstance();
 
   bool is_system_suspended_ GUARDED_BY(is_system_suspended_lock_) = false;
-  Lock is_system_suspended_lock_;
+  mutable Lock is_system_suspended_lock_;
   TimeTicks last_system_resume_time_ GUARDED_BY(is_system_suspended_lock_);
 
   PowerStateObserver::BatteryPowerStatus battery_power_status_
       GUARDED_BY(battery_power_status_lock_) =
           PowerStateObserver::BatteryPowerStatus::kExternalPower;
-  Lock battery_power_status_lock_;
+  mutable Lock battery_power_status_lock_;
 
   PowerThermalObserver::DeviceThermalState power_thermal_state_
       GUARDED_BY(power_thermal_state_lock_) =

base/power_monitor/power_monitor_device_source.cc

@@ -8,7 +8,7 @@
 
 namespace base {
 
-bool PowerMonitorDeviceSource::IsOnBatteryPower() {
+bool PowerMonitorDeviceSource::IsOnBatteryPower() const {
   return GetBatteryPowerStatus() ==
          PowerStateObserver::BatteryPowerStatus::kBatteryPower;
 }

base/power_monitor/power_monitor_device_source.h

@@ -62,7 +62,8 @@ class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
 
   // These two methods is used for handling thermal state update requests, such
   // as asking for initial state when starting lisitening to thermal change.
-  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() override;
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState()
+      const override;
   void SetCurrentThermalState(
       PowerThermalObserver::DeviceThermalState state) override;
 #endif
@@ -109,29 +110,31 @@ class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
   // Platform-specific method to check whether the system is currently
   // running on battery power.  Returns true if running on batteries,
   // false otherwise.
-  bool IsOnBatteryPower() final;
+  bool IsOnBatteryPower() const final;
 
   // Platform-specific method to check whether the system is currently
   // running on battery power. Returns kBatteryPower if running on battery,
   // kExternalPower if running on external power or kUnknown if the power
   // state is unknown (for example, during early process lifetime when the
   // state hasn't been obtained yet).
-  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus();
+  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() const;
 
 #if BUILDFLAG(IS_ANDROID)
-  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() override;
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState()
-  int GetRemainingBatteryCapacity() override;
+      const override;
+  int GetRemainingBatteryCapacity() const override;
 #endif  // BUILDFLAG(IS_ANDROID)
 
 #if BUILDFLAG(IS_WIN)
   // PowerMonitorSource:
-  int GetInitialSpeedLimit() override;
+  int GetInitialSpeedLimit() const override;
 #endif  // BUILDFLAG(IS_WIN)
 
 #if BUILDFLAG(IS_MAC)
   // PowerMonitorSource:
-  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() override;
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState()
-  int GetInitialSpeedLimit() override;
+      const override;
+  int GetInitialSpeedLimit() const override;
 
   // Retrieves the current battery state to update `is_on_battery_`.
   void GetBatteryState();

base/power_monitor/power_monitor_device_source_android.cc

@@ -83,20 +83,20 @@ void JNI_PowerMonitor_OnThermalStatusChanged(JNIEnv* env, int thermal_status) {
 }  // namespace android
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
   JNIEnv* env = jni_zero::AttachCurrentThread();
   int battery_power =
       base::android::Java_PowerMonitor_getBatteryPowerStatus(env);
   return static_cast<PowerStateObserver::BatteryPowerStatus>(battery_power);
 }
 
-int PowerMonitorDeviceSource::GetRemainingBatteryCapacity() {
+int PowerMonitorDeviceSource::GetRemainingBatteryCapacity() const {
   JNIEnv* env = jni_zero::AttachCurrentThread();
   return base::android::Java_PowerMonitor_getRemainingBatteryCapacity(env);
 }
 
 PowerThermalObserver::DeviceThermalState
-PowerMonitorDeviceSource::GetCurrentThermalState() {
+PowerMonitorDeviceSource::GetCurrentThermalState() const {
   JNIEnv* env = jni_zero::AttachCurrentThread();
   return android::MapToDeviceThermalState(
       android::Java_PowerMonitor_getCurrentThermalStatus(env));

base/power_monitor/power_monitor_device_source_chromeos.cc

@@ -38,23 +38,24 @@ void PowerMonitorDeviceSource::HandleSystemResumed() {
 }
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
   return g_battery_power_status;
 }
 
 // static
 void PowerMonitorDeviceSource::ThermalEventReceived(
     PowerThermalObserver::DeviceThermalState state) {
-  if (!PowerMonitor::IsInitialized()) {
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-    PowerMonitor::Initialize(std::make_unique<PowerMonitorDeviceSource>());
+  if (!power_monitor->IsInitialized()) {
+    power_monitor->Initialize(std::make_unique<PowerMonitorDeviceSource>());
   }
-  PowerMonitor::SetCurrentThermalState(state);
+  power_monitor->SetCurrentThermalState(state);
 
   ProcessThermalEvent(state);
 }
 
 PowerThermalObserver::DeviceThermalState
-PowerMonitorDeviceSource::GetCurrentThermalState() {
+PowerMonitorDeviceSource::GetCurrentThermalState() const {
   return current_thermal_state_;
 }
 

base/power_monitor/power_monitor_device_source_ios.mm

@@ -11,7 +11,7 @@
 namespace base {
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
 #if TARGET_IPHONE_SIMULATOR
   return PowerStateObserver::BatteryPowerStatus::kExternalPower;
 #else

base/power_monitor/power_monitor_device_source_mac.mm

@@ -20,11 +20,11 @@
 namespace base {
 
 PowerThermalObserver::DeviceThermalState
-PowerMonitorDeviceSource::GetCurrentThermalState() {
+PowerMonitorDeviceSource::GetCurrentThermalState() const {
   return thermal_state_observer_->GetCurrentThermalState();
 }
 
-int PowerMonitorDeviceSource::GetInitialSpeedLimit() {
+int PowerMonitorDeviceSource::GetInitialSpeedLimit() const {
   return thermal_state_observer_->GetCurrentSpeedLimit();
 }
 
@@ -96,7 +96,7 @@ void PowerMonitorDeviceSource::PlatformDestroy() {
 }
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
   return battery_power_status_;
 }
 

base/power_monitor/power_monitor_device_source_stub.cc

@@ -8,7 +8,7 @@
 namespace base {
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
   return PowerStateObserver::BatteryPowerStatus::kExternalPower;
 }
 

base/power_monitor/power_monitor_device_source_win.cc

@@ -76,7 +76,7 @@ void PowerMonitorDeviceSource::PlatformDestroy() {
 }
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorDeviceSource::GetBatteryPowerStatus() {
+PowerMonitorDeviceSource::GetBatteryPowerStatus() const {
   SYSTEM_POWER_STATUS status;
   if (!::GetSystemPowerStatus(&status)) {
     DPLOG(ERROR) << "GetSystemPowerStatus failed";
@@ -87,7 +87,7 @@ PowerMonitorDeviceSource::GetBatteryPowerStatus() {
              : PowerStateObserver::BatteryPowerStatus::kExternalPower;
 }
 
-int PowerMonitorDeviceSource::GetInitialSpeedLimit() {
+int PowerMonitorDeviceSource::GetInitialSpeedLimit() const {
   // Returns the maximum value once at start. Subsequent actual values will be
   // provided asynchronously via callbacks instead.
   return PowerThermalObserver::kSpeedLimitMax;

base/power_monitor/power_monitor_source.cc

@@ -15,11 +15,11 @@ PowerMonitorSource::PowerMonitorSource() = default;
 PowerMonitorSource::~PowerMonitorSource() = default;
 
 PowerThermalObserver::DeviceThermalState
-PowerMonitorSource::GetCurrentThermalState() {
+PowerMonitorSource::GetCurrentThermalState() const {
   return PowerThermalObserver::DeviceThermalState::kUnknown;
 }
 
-int PowerMonitorSource::GetInitialSpeedLimit() {
+int PowerMonitorSource::GetInitialSpeedLimit() const {
   return PowerThermalObserver::kSpeedLimitMax;
 }
 
@@ -27,43 +27,47 @@ void PowerMonitorSource::SetCurrentThermalState(
     PowerThermalObserver::DeviceThermalState state) {}
 
 #if BUILDFLAG(IS_ANDROID)
-int PowerMonitorSource::GetRemainingBatteryCapacity() {
+int PowerMonitorSource::GetRemainingBatteryCapacity() const {
   return 0;
 }
 #endif  // BUILDFLAG(IS_ANDROID)
 
 // static
 void PowerMonitorSource::ProcessPowerEvent(PowerEvent event_id) {
-  if (!PowerMonitor::IsInitialized())
+  auto* power_monitor = base::PowerMonitor::GetInstance();
+  if (!power_monitor->IsInitialized()) {
     return;
+  }
 
   switch (event_id) {
     case POWER_STATE_EVENT:
-      PowerMonitor::NotifyPowerStateChange(
+      power_monitor->NotifyPowerStateChange(
-          PowerMonitor::Source()->GetBatteryPowerStatus());
+          power_monitor->Source()->GetBatteryPowerStatus());
       break;
       case RESUME_EVENT:
-        PowerMonitor::NotifyResume();
+        power_monitor->NotifyResume();
-      break;
+        break;
       case SUSPEND_EVENT:
-        PowerMonitor::NotifySuspend();
+        power_monitor->NotifySuspend();
-      break;
+        break;
   }
 }
 
 // static
 void PowerMonitorSource::ProcessThermalEvent(
     PowerThermalObserver::DeviceThermalState new_thermal_state) {
-  if (!PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    return;
+      power_monitor->IsInitialized()) {
-  PowerMonitor::NotifyThermalStateChange(new_thermal_state);
+    power_monitor->NotifyThermalStateChange(new_thermal_state);
+  }
 }
 
 // static
 void PowerMonitorSource::ProcessSpeedLimitEvent(int speed_limit) {
-  if (!PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    return;
+      power_monitor->IsInitialized()) {
-  PowerMonitor::NotifySpeedLimitChange(speed_limit);
+    power_monitor->NotifySpeedLimitChange(speed_limit);
+  }
 }
 
 // static

base/power_monitor/power_monitor_source.h

@@ -31,14 +31,15 @@ class BASE_EXPORT PowerMonitorSource {
 
   // Reads the current DeviceThermalState, if available on the platform.
   // Otherwise, returns kUnknown.
-  virtual PowerThermalObserver::DeviceThermalState GetCurrentThermalState();
+  virtual PowerThermalObserver::DeviceThermalState GetCurrentThermalState()
+      const;
 
   // Reads the initial operating system CPU speed limit, if available on the
   // platform. Otherwise returns PowerThermalObserver::kSpeedLimitMax.
   // Only called on the main thread in PowerMonitor::Initialize().
   // The actual speed limit value will be updated asynchronously via the
   // ProcessSpeedLimitEvent() if/when the value changes.
-  virtual int GetInitialSpeedLimit();
+  virtual int GetInitialSpeedLimit() const;
 
   // Update the result of thermal state.
   virtual void SetCurrentThermalState(
@@ -46,9 +47,9 @@ class BASE_EXPORT PowerMonitorSource {
 
   // Platform-specific method to check whether the system is currently
   // running on battery power.
-  virtual bool IsOnBatteryPower() = 0;
+  virtual bool IsOnBatteryPower() const = 0;
 
-  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() {
+  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() const {
     return IsOnBatteryPower()
                ? PowerStateObserver::BatteryPowerStatus::kBatteryPower
                : PowerStateObserver::BatteryPowerStatus::kExternalPower;
@@ -56,7 +57,7 @@ class BASE_EXPORT PowerMonitorSource {
 
 #if BUILDFLAG(IS_ANDROID)
   // Read and return the current remaining battery capacity (microampere-hours).
-  virtual int GetRemainingBatteryCapacity();
+  virtual int GetRemainingBatteryCapacity() const;
 #endif  // BUILDFLAG(IS_ANDROID)
 
   static const char* DeviceThermalStateToString(

base/power_monitor/power_monitor_unittest.cc

@@ -40,10 +40,11 @@ TEST_F(PowerMonitorTest, PowerNotifications) {
   PowerMonitorInitialize();
 
   PowerMonitorTestObserver observers[kObservers];
+  auto* power_monitor = PowerMonitor::GetInstance();
   for (auto& index : observers) {
-    PowerMonitor::AddPowerSuspendObserver(&index);
+    power_monitor->AddPowerSuspendObserver(&index);
-    PowerMonitor::AddPowerStateObserver(&index);
+    power_monitor->AddPowerStateObserver(&index);
-    PowerMonitor::AddPowerThermalObserver(&index);
+    power_monitor->AddPowerThermalObserver(&index);
   }
 
   // Sending resume when not suspended should have no effect.
@@ -122,15 +123,16 @@ TEST_F(PowerMonitorTest, PowerNotifications) {
             PowerThermalObserver::DeviceThermalState::kFair);
 
   for (auto& index : observers) {
-    PowerMonitor::RemovePowerSuspendObserver(&index);
+    power_monitor->RemovePowerSuspendObserver(&index);
-    PowerMonitor::RemovePowerStateObserver(&index);
+    power_monitor->RemovePowerStateObserver(&index);
-    PowerMonitor::RemovePowerThermalObserver(&index);
+    power_monitor->RemovePowerThermalObserver(&index);
   }
 }
 
 TEST_F(PowerMonitorTest, ThermalThrottling) {
   PowerMonitorTestObserver observer;
-  PowerMonitor::AddPowerThermalObserver(&observer);
+  auto* power_monitor = PowerMonitor::GetInstance();
+  power_monitor->AddPowerThermalObserver(&observer);
 
   PowerMonitorInitialize();
 
@@ -147,20 +149,21 @@ TEST_F(PowerMonitorTest, ThermalThrottling) {
     EXPECT_EQ(observer.last_thermal_state(), state);
   }
 
-  PowerMonitor::RemovePowerThermalObserver(&observer);
+  power_monitor->RemovePowerThermalObserver(&observer);
 }
 
 TEST_F(PowerMonitorTest, AddPowerSuspendObserverBeforeAndAfterInitialization) {
   PowerMonitorTestObserver observer1;
   PowerMonitorTestObserver observer2;
+  auto* power_monitor = PowerMonitor::GetInstance();
 
   // An observer is added before the PowerMonitor initialization.
-  PowerMonitor::AddPowerSuspendObserver(&observer1);
+  power_monitor->AddPowerSuspendObserver(&observer1);
 
   PowerMonitorInitialize();
 
   // An observer is added after the PowerMonitor initialization.
-  PowerMonitor::AddPowerSuspendObserver(&observer2);
+  power_monitor->AddPowerSuspendObserver(&observer2);
 
   // Simulate suspend/resume notifications.
   source().GenerateSuspendEvent();
@@ -173,21 +176,22 @@ TEST_F(PowerMonitorTest, AddPowerSuspendObserverBeforeAndAfterInitialization) {
   EXPECT_EQ(observer1.resumes(), 1);
   EXPECT_EQ(observer2.resumes(), 1);
 
-  PowerMonitor::RemovePowerSuspendObserver(&observer1);
+  power_monitor->RemovePowerSuspendObserver(&observer1);
-  PowerMonitor::RemovePowerSuspendObserver(&observer2);
+  power_monitor->RemovePowerSuspendObserver(&observer2);
 }
 
 TEST_F(PowerMonitorTest, AddPowerStateObserverBeforeAndAfterInitialization) {
   PowerMonitorTestObserver observer1;
   PowerMonitorTestObserver observer2;
+  auto* power_monitor = PowerMonitor::GetInstance();
 
   // An observer is added before the PowerMonitor initialization.
-  PowerMonitor::AddPowerStateObserver(&observer1);
+  power_monitor->AddPowerStateObserver(&observer1);
 
   PowerMonitorInitialize();
 
   // An observer is added after the PowerMonitor initialization.
-  PowerMonitor::AddPowerStateObserver(&observer2);
+  power_monitor->AddPowerStateObserver(&observer2);
 
   // Simulate power state transitions (e.g. battery on/off).
   EXPECT_EQ(observer1.power_state_changes(), 0);
@@ -201,41 +205,43 @@ TEST_F(PowerMonitorTest, AddPowerStateObserverBeforeAndAfterInitialization) {
   EXPECT_EQ(observer1.power_state_changes(), 2);
   EXPECT_EQ(observer2.power_state_changes(), 2);
 
-  PowerMonitor::RemovePowerStateObserver(&observer1);
+  power_monitor->RemovePowerStateObserver(&observer1);
-  PowerMonitor::RemovePowerStateObserver(&observer2);
+  power_monitor->RemovePowerStateObserver(&observer2);
 }
 
 TEST_F(PowerMonitorTest, SuspendStateReturnedFromAddObserver) {
   PowerMonitorTestObserver observer1;
   PowerMonitorTestObserver observer2;
+  auto* power_monitor = PowerMonitor::GetInstance();
 
   PowerMonitorInitialize();
 
-  EXPECT_FALSE(
+  EXPECT_FALSE(power_monitor->AddPowerSuspendObserverAndReturnSuspendedState(
-      PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(&observer1));
+      &observer1));
 
   source().GenerateSuspendEvent();
 
-  EXPECT_TRUE(
+  EXPECT_TRUE(power_monitor->AddPowerSuspendObserverAndReturnSuspendedState(
-      PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(&observer2));
+      &observer2));
 
   EXPECT_EQ(observer1.suspends(), 1);
   EXPECT_EQ(observer2.suspends(), 0);
   EXPECT_EQ(observer1.resumes(), 0);
   EXPECT_EQ(observer2.resumes(), 0);
 
-  PowerMonitor::RemovePowerSuspendObserver(&observer1);
+  power_monitor->RemovePowerSuspendObserver(&observer1);
-  PowerMonitor::RemovePowerSuspendObserver(&observer2);
+  power_monitor->RemovePowerSuspendObserver(&observer2);
 }
 
 TEST_F(PowerMonitorTest, PowerStateReturnedFromAddObserver) {
   PowerMonitorTestObserver observer1;
   PowerMonitorTestObserver observer2;
+  auto* power_monitor = PowerMonitor::GetInstance();
 
   PowerMonitorInitialize();
 
   // An observer is added before the on-battery notification.
-  EXPECT_NE(PowerMonitor::AddPowerStateObserverAndReturnBatteryPowerStatus(
+  EXPECT_NE(power_monitor->AddPowerStateObserverAndReturnBatteryPowerStatus(
                 &observer1),
             PowerStateObserver::BatteryPowerStatus::kBatteryPower);
 
@@ -243,15 +249,15 @@ TEST_F(PowerMonitorTest, PowerStateReturnedFromAddObserver) {
       PowerStateObserver::BatteryPowerStatus::kBatteryPower);
 
   // An observer is added after the on-battery notification.
-  EXPECT_EQ(PowerMonitor::AddPowerStateObserverAndReturnBatteryPowerStatus(
+  EXPECT_EQ(power_monitor->AddPowerStateObserverAndReturnBatteryPowerStatus(
                 &observer2),
             PowerStateObserver::BatteryPowerStatus::kBatteryPower);
 
   EXPECT_EQ(observer1.power_state_changes(), 1);
   EXPECT_EQ(observer2.power_state_changes(), 0);
 
-  PowerMonitor::RemovePowerStateObserver(&observer1);
+  power_monitor->RemovePowerStateObserver(&observer1);
-  PowerMonitor::RemovePowerStateObserver(&observer2);
+  power_monitor->RemovePowerStateObserver(&observer2);
 }
 
 }  // namespace test

base/power_monitor/speed_limit_observer_win.cc

@@ -91,7 +91,7 @@ SpeedLimitObserverWin::~SpeedLimitObserverWin() {
   timer_.Stop();
 }
 
-int SpeedLimitObserverWin::GetCurrentSpeedLimit() {
+int SpeedLimitObserverWin::GetCurrentSpeedLimit() const {
   const int kSpeedLimitMax = PowerThermalObserver::kSpeedLimitMax;
 
   int idleness_percent = 0;
@@ -172,7 +172,7 @@ void SpeedLimitObserverWin::OnTimerTick() {
 #endif  // BUILDFLAG(ENABLE_BASE_TRACING)
 }
 
-float SpeedLimitObserverWin::EstimateThrottlingLevel() {
+float SpeedLimitObserverWin::EstimateThrottlingLevel() const {
   float throttling_level = 0.f;
 
   // Populate the PROCESSOR_POWER_INFORMATION structures for all logical CPUs

base/power_monitor/speed_limit_observer_win.h

@@ -34,9 +34,9 @@ class BASE_EXPORT SpeedLimitObserverWin final {
   ~SpeedLimitObserverWin();
 
  private:
-  int GetCurrentSpeedLimit();
+  int GetCurrentSpeedLimit() const;
   void OnTimerTick();
-  float EstimateThrottlingLevel();
+  float EstimateThrottlingLevel() const;
 
   size_t num_cpus() const { return num_cpus_; }
 
@@ -54,7 +54,7 @@ class BASE_EXPORT SpeedLimitObserverWin final {
   // sample rate is one sample per seconds but the existing choice is rather
   // ad-hoc and not based on any deeper analysis into exact frequency
   // characteristics of the underlying process.
-  MovingAverage<int, int64_t> moving_average_;
+  mutable MovingAverage<int, int64_t> moving_average_;
   // Max speed-limit value is 100 (%) and it is also used in cases where the
   // native Windows API(s) fail.
   int speed_limit_ = PowerThermalObserver::kSpeedLimitMax;

base/power_monitor/thermal_state_observer_mac.h

@@ -37,7 +37,7 @@ class BASE_EXPORT ThermalStateObserverMac {
   ~ThermalStateObserverMac();
 
   PowerThermalObserver::DeviceThermalState GetCurrentThermalState();
-  int GetCurrentSpeedLimit();
+  int GetCurrentSpeedLimit() const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(ThermalStateObserverMacTest, StateChange);

base/power_monitor/thermal_state_observer_mac.mm

@@ -109,7 +109,7 @@ ThermalStateObserverMac::GetCurrentThermalState() {
   return NSProcessInfoThermalStateToDeviceThermalState(nsinfo_state);
 }
 
-int ThermalStateObserverMac::GetCurrentSpeedLimit() {
+int ThermalStateObserverMac::GetCurrentSpeedLimit() const {
   apple::ScopedCFTypeRef<CFDictionaryRef> dictionary;
   IOReturn result = IOPMCopyCPUPowerStatus(dictionary.InitializeInto());
   if (result != kIOReturnSuccess) {

base/task/sequence_manager/thread_controller_power_monitor.cc

@@ -28,18 +28,19 @@ bool g_use_thread_controller_power_monitor_ = false;
 ThreadControllerPowerMonitor::ThreadControllerPowerMonitor() = default;
 
 ThreadControllerPowerMonitor::~ThreadControllerPowerMonitor() {
-  PowerMonitor::RemovePowerSuspendObserver(this);
+  PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 void ThreadControllerPowerMonitor::BindToCurrentThread() {
   // Occasionally registration happens twice (i.e. when the
   // ThreadController::SetDefaultTaskRunner() re-initializes the
   // ThreadController).
+  auto* power_monitor = PowerMonitor::GetInstance();
   if (is_observer_registered_)
-    PowerMonitor::RemovePowerSuspendObserver(this);
+    power_monitor->RemovePowerSuspendObserver(this);
 
   // Register the observer to deliver notifications on the current thread.
-  PowerMonitor::AddPowerSuspendObserver(this);
+  power_monitor->AddPowerSuspendObserver(this);
   is_observer_registered_ = true;
 }
 

base/test/power_monitor_test.cc

@@ -19,9 +19,10 @@ class PowerMonitorTestSource : public PowerMonitorSource {
   ~PowerMonitorTestSource() override = default;
 
   // Retrieve current states.
-  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() override;
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState()
-  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus();
+      const override;
-  bool IsOnBatteryPower() override;
+  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() const;
+  bool IsOnBatteryPower() const override;
 
   // Sends asynchronous notifications to registered observers.
   void Suspend();
@@ -51,7 +52,7 @@ class PowerMonitorTestSource : public PowerMonitorSource {
 };
 
 PowerThermalObserver::DeviceThermalState
-PowerMonitorTestSource::GetCurrentThermalState() {
+PowerMonitorTestSource::GetCurrentThermalState() const {
   return current_thermal_state_;
 }
 
@@ -98,11 +99,11 @@ void PowerMonitorTestSource::GenerateResumeEvent() {
 }
 
 PowerStateObserver::BatteryPowerStatus
-PowerMonitorTestSource::GetBatteryPowerStatus() {
+PowerMonitorTestSource::GetBatteryPowerStatus() const {
   return test_power_status_;
 }
 
-bool PowerMonitorTestSource::IsOnBatteryPower() {
+bool PowerMonitorTestSource::IsOnBatteryPower() const {
   return test_power_status_ ==
          PowerStateObserver::BatteryPowerStatus::kBatteryPower;
 }
@@ -123,24 +124,25 @@ void PowerMonitorTestSource::GenerateSpeedLimitEvent(int speed_limit) {
 ScopedPowerMonitorTestSource::ScopedPowerMonitorTestSource() {
   auto power_monitor_test_source = std::make_unique<PowerMonitorTestSource>();
   power_monitor_test_source_ = power_monitor_test_source.get();
-  base::PowerMonitor::Initialize(std::move(power_monitor_test_source));
+  base::PowerMonitor::GetInstance()->Initialize(
+      std::move(power_monitor_test_source));
 }
 
 ScopedPowerMonitorTestSource::~ScopedPowerMonitorTestSource() {
-  base::PowerMonitor::ShutdownForTesting();
+  base::PowerMonitor::GetInstance()->ShutdownForTesting();
 }
 
 PowerThermalObserver::DeviceThermalState
-ScopedPowerMonitorTestSource::GetCurrentThermalState() {
+ScopedPowerMonitorTestSource::GetCurrentThermalState() const {
   return power_monitor_test_source_->GetCurrentThermalState();
 }
 
-bool ScopedPowerMonitorTestSource::IsOnBatteryPower() {
+bool ScopedPowerMonitorTestSource::IsOnBatteryPower() const {
   return power_monitor_test_source_->IsOnBatteryPower();
 }
 
 PowerStateObserver::BatteryPowerStatus
-ScopedPowerMonitorTestSource::GetBatteryPowerStatus() {
+ScopedPowerMonitorTestSource::GetBatteryPowerStatus() const {
   return power_monitor_test_source_->GetBatteryPowerStatus();
 }
 

base/test/power_monitor_test.h

@@ -37,9 +37,9 @@ class ScopedPowerMonitorTestSource {
       delete;
 
   // Retrieve current states.
-  PowerThermalObserver::DeviceThermalState GetCurrentThermalState();
+  PowerThermalObserver::DeviceThermalState GetCurrentThermalState() const;
-  bool IsOnBatteryPower();
+  bool IsOnBatteryPower() const;
-  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus();
+  PowerStateObserver::BatteryPowerStatus GetBatteryPowerStatus() const;
 
   // Sends asynchronous notifications to registered observers.
   void Suspend();

base/threading/hang_watcher.cc

@@ -561,7 +561,7 @@ std::string HangWatcher::GetTimeSinceLastSystemPowerResumeCrashKeyValue()
   DCHECK_CALLED_ON_VALID_THREAD(hang_watcher_thread_checker_);
 
   const TimeTicks last_system_power_resume_time =
-      PowerMonitor::GetLastSystemResumeTime();
+      PowerMonitor::GetInstance()->GetLastSystemResumeTime();
   if (last_system_power_resume_time.is_null())
     return "Never suspended";
   if (last_system_power_resume_time == TimeTicks::Max())

base/timer/hi_res_timer_manager_win.cc

@@ -40,10 +40,11 @@ HighResolutionTimerManager::HighResolutionTimerManager()
   // we won't receive power state change callbacks and
   // hi_res_clock_available_ will remain at its initial value.
   if (HighResolutionTimerAllowed()) {
-    DCHECK(PowerMonitor::IsInitialized());
+    auto* power_monitor = base::PowerMonitor::GetInstance();
-    PowerMonitor::AddPowerSuspendObserver(this);
+    DCHECK(power_monitor->IsInitialized());
+    power_monitor->AddPowerSuspendObserver(this);
     const bool on_battery =
-        PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(this);
+        power_monitor->AddPowerStateObserverAndReturnOnBatteryState(this);
     UseHiResClock(!on_battery);
 
     // Start polling the high resolution timer usage.
@@ -55,8 +56,9 @@ HighResolutionTimerManager::HighResolutionTimerManager()
 
 HighResolutionTimerManager::~HighResolutionTimerManager() {
   if (HighResolutionTimerAllowed()) {
-    PowerMonitor::RemovePowerSuspendObserver(this);
+    auto* power_monitor = base::PowerMonitor::GetInstance();
-    PowerMonitor::RemovePowerStateObserver(this);
+    power_monitor->RemovePowerSuspendObserver(this);
+    power_monitor->RemovePowerStateObserver(this);
     UseHiResClock(false);
   }
 }

base/timer/wall_clock_timer.cc

@@ -51,14 +51,14 @@ void WallClockTimer::OnResume() {
 
 void WallClockTimer::AddObserver() {
   if (!observer_added_) {
-    PowerMonitor::AddPowerSuspendObserver(this);
+    PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
     observer_added_ = true;
   }
 }
 
 void WallClockTimer::RemoveObserver() {
   if (observer_added_) {
-    PowerMonitor::RemovePowerSuspendObserver(this);
+    PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
     observer_added_ = false;
   }
 }

chrome/browser/ash/login/signin/offline_signin_limiter.cc

@@ -75,7 +75,7 @@ void OfflineSigninLimiter::SignedIn(UserContext::AuthFlow auth_flow) {
       base::BindRepeating(&OfflineSigninLimiter::UpdateLockScreenLimit,
                           base::Unretained(this)));
   // Start listening to power state.
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 
   // Start listening to session lock state
   auto* session_manager = session_manager::SessionManager::Get();
@@ -122,7 +122,7 @@ OfflineSigninLimiter::OfflineSigninLimiter(Profile* profile,
           std::make_unique<base::WallClockTimer>()) {}
 
 OfflineSigninLimiter::~OfflineSigninLimiter() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   auto* session_manager = session_manager::SessionManager::Get();
   if (session_manager) {
     session_manager->RemoveObserver(this);

chrome/browser/content_settings/one_time_permission_provider.cc

@@ -39,11 +39,11 @@ OneTimePermissionProvider::OneTimePermissionProvider(
   // main function for the browser process is run (which initializes the HCSM).
   // For this reason, the PowerMonitor is always initialized before the observer
   // is added here.
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 }
 
 OneTimePermissionProvider::~OneTimePermissionProvider() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 // TODO(b/307193732): handle the PartitionKey in all relevant methods, including

chrome/browser/download/bubble/download_display_controller.cc

@@ -101,11 +101,11 @@ DownloadDisplayController::DownloadDisplayController(
   if (display) {
     MaybeShowButtonWhenCreated();
   }
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 }
 
 DownloadDisplayController::~DownloadDisplayController() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 void DownloadDisplayController::OnNewItem(bool show_animation) {

chrome/browser/extensions/extension_protocols_unittest.cc

@@ -276,7 +276,7 @@ class ExtensionProtocolsTestBase : public testing::Test,
     loader_factory_.reset();
     content_verifier_->Shutdown();
     // Shut down the PowerMonitor if initialized.
-    base::PowerMonitor::ShutdownForTesting();
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
   }
 
   GetResult RequestOrLoad(const GURL& url,

chrome/browser/feedback/system_logs/log_sources/performance_log_source_unittest.cc

@@ -64,7 +64,7 @@ class PerformanceLogSourceTest : public BrowserWithTestWindowTest {
   void SetUp() override { environment_.SetUp(local_state_); }
 
   void TearDown() override {
-    base::PowerMonitor::ShutdownForTesting();
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
     environment_.TearDown();
   }
 

chrome/browser/media/media_foundation_service_monitor.cc

@@ -300,7 +300,7 @@ void MediaFoundationServiceMonitor::Initialize() {
     AddGlobalSample(kSignificantPlayback, base::Time::Now());
 
   content::ServiceProcessHost::AddObserver(this);
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
 }
 

chrome/browser/metrics/perf/profile_provider_chromeos.cc

@@ -57,7 +57,7 @@ ProfileProvider::ProfileProvider()
 ProfileProvider::~ProfileProvider() {
   ash::LoginState::Get()->RemoveObserver(this);
   chromeos::PowerManagerClient::Get()->RemoveObserver(this);
-  base::PowerMonitor::RemovePowerThermalObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerThermalObserver(this);
   if (jank_monitor_) {
     jank_monitor_->RemoveObserver(this);
     jank_monitor_->Destroy();
@@ -82,7 +82,8 @@ void ProfileProvider::Init() {
 
   // Register as an observer of thermal state changes.
   base::PowerThermalObserver::DeviceThermalState thermal_state =
-      base::PowerMonitor::AddPowerStateObserverAndReturnPowerThermalState(this);
+      base::PowerMonitor::GetInstance()
+          ->AddPowerStateObserverAndReturnPowerThermalState(this);
   OnThermalStateChange(thermal_state);
 
   // Check the login state. At the time of writing, this class is instantiated

chrome/browser/metrics/tab_stats/tab_stats_tracker.cc

@@ -63,12 +63,13 @@ TabStatsTracker* g_tab_stats_tracker_instance = nullptr;
 
 void UmaHistogramCounts10000WithBatteryStateVariant(const char* histogram_name,
                                                     size_t value) {
-  DCHECK(base::PowerMonitor::IsInitialized());
+  auto* power_monitor = base::PowerMonitor::GetInstance();
+  DCHECK(power_monitor->IsInitialized());
 
   base::UmaHistogramCounts10000(histogram_name, value);
 
   const char* suffix =
-      base::PowerMonitor::IsOnBatteryPower() ? ".OnBattery" : ".PluggedIn";
+      power_monitor->IsOnBatteryPower() ? ".OnBattery" : ".PluggedIn";
 
   base::UmaHistogramCounts10000(base::StrCat({histogram_name, suffix}), value);
 }
@@ -147,7 +148,7 @@ TabStatsTracker::TabStatsTracker(PrefService* pref_service)
   }
 
   browser_list->AddObserver(this);
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 
   // Setup daily reporting of the stats aggregated in |tab_stats_data_store|.
   daily_event_->AddObserver(std::make_unique<TabStatsDailyObserver>(
@@ -169,7 +170,7 @@ TabStatsTracker::TabStatsTracker(PrefService* pref_service)
 TabStatsTracker::~TabStatsTracker() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   BrowserList::GetInstance()->RemoveObserver(this);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   g_browser_process->GetTabManager()->RemoveObserver(this);
 }
 

chrome/browser/metrics/tab_stats/tab_stats_tracker_unittest.cc

@@ -35,8 +35,9 @@ namespace {
 using TabsStats = TabStatsDataStore::TabsStats;
 
 std::string GetHistogramNameWithBatteryStateSuffix(const char* histogram_name) {
-  const char* suffix =
+  const char* suffix = base::PowerMonitor::GetInstance()->IsOnBatteryPower()
-      base::PowerMonitor::IsOnBatteryPower() ? ".OnBattery" : ".PluggedIn";
+                           ? ".OnBattery"
+                           : ".PluggedIn";
 
   return base::StrCat({histogram_name, suffix});
 }

chrome/browser/metrics/usage_scenario/system_event_provider.cc

@@ -9,13 +9,17 @@
 
 SystemEventProvider::SystemEventProvider(UsageScenarioDataStoreImpl* data_store)
     : data_store_(data_store) {
-  if (base::PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+      power_monitor->IsInitialized()) {
+    power_monitor->AddPowerSuspendObserver(this);
+  }
 }
 
 SystemEventProvider::~SystemEventProvider() {
-  if (base::PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+      power_monitor->IsInitialized()) {
+    power_monitor->RemovePowerSuspendObserver(this);
+  }
 }
 
 void SystemEventProvider::OnSuspend() {

chrome/browser/performance_manager/test_support/fake_power_monitor_source.cc

@@ -6,7 +6,7 @@
 
 namespace performance_manager {
 
-bool FakePowerMonitorSource::IsOnBatteryPower() {
+bool FakePowerMonitorSource::IsOnBatteryPower() const {
   return on_battery_power_;
 }
 

chrome/browser/performance_manager/test_support/fake_power_monitor_source.h

@@ -12,7 +12,7 @@ namespace performance_manager {
 
 class FakePowerMonitorSource : public base::PowerMonitorSource {
  public:
-  bool IsOnBatteryPower() override;
+  bool IsOnBatteryPower() const override;
   void SetOnBatteryPower(bool on_battery_power);
 
  private:

chrome/browser/performance_manager/test_support/test_user_performance_tuning_manager_environment.cc

@@ -72,7 +72,7 @@ void TestUserPerformanceTuningManagerEnvironment::SetUp(
 #endif
   auto source = std::make_unique<FakePowerMonitorSource>();
   power_monitor_source_ = source.get();
-  base::PowerMonitor::Initialize(std::move(source));
+  base::PowerMonitor::GetInstance()->Initialize(std::move(source));
 
   if (!sampling_event_source) {
     auto test_sampling_event_source =
@@ -114,7 +114,7 @@ void TestUserPerformanceTuningManagerEnvironment::TearDown() {
   user_performance_tuning_manager_.reset();
   battery_saver_mode_manager_.reset();
   battery_sampler_.reset();
-  base::PowerMonitor::ShutdownForTesting();
+  base::PowerMonitor::GetInstance()->ShutdownForTesting();
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   if (tear_down_power_manager_client_) {
     chromeos::PowerManagerClient::Shutdown();

chrome/browser/performance_manager/user_tuning/battery_saver_mode_manager.cc

@@ -212,7 +212,8 @@ class DesktopBatterySaverProvider
             base::Unretained(this)));
 
     on_battery_power_ =
-        base::PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(this);
+        base::PowerMonitor::GetInstance()
+            ->AddPowerStateObserverAndReturnOnBatteryState(this);
 
     base::BatteryStateSampler* battery_state_sampler =
         base::BatteryStateSampler::Get();
@@ -226,7 +227,7 @@ class DesktopBatterySaverProvider
   }
 
   ~DesktopBatterySaverProvider() override {
-    base::PowerMonitor::RemovePowerStateObserver(this);
+    base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
   }
 
   // BatterySaverProvider:

chrome/browser/performance_manager/user_tuning/battery_saver_mode_manager_unittest.cc

@@ -119,7 +119,7 @@ class BatterySaverModeManagerTest : public ::testing::Test {
   void SetUp() override {
     auto source = std::make_unique<FakePowerMonitorSource>();
     power_monitor_source_ = source.get();
-    base::PowerMonitor::Initialize(std::move(source));
+    base::PowerMonitor::GetInstance()->Initialize(std::move(source));
 
     performance_manager::user_tuning::prefs::RegisterLocalStatePrefs(
         local_state_.registry());
@@ -147,7 +147,9 @@ class BatterySaverModeManagerTest : public ::testing::Test {
     manager()->Start();
   }
 
-  void TearDown() override { base::PowerMonitor::ShutdownForTesting(); }
+  void TearDown() override {
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
+  }
 
   BatterySaverModeManager* manager() {
     return BatterySaverModeManager::GetInstance();

chrome/browser/predictors/loading_predictor.cc

@@ -93,8 +93,8 @@ bool IsPreconnectExpensive() {
 #if BUILDFLAG(IS_ANDROID)
   // Preconnecting is expensive while on battery power and cellular data and
   // the radio signal is weak.
-  if ((base::PowerMonitor::IsInitialized() &&
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-       !base::PowerMonitor::IsOnBatteryPower()) ||
+      (power_monitor->IsInitialized() && !power_monitor->IsOnBatteryPower()) ||
       (base::android::RadioUtils::GetConnectionType() !=
        base::android::RadioConnectionType::kCell)) {
     return false;

chrome/browser/smart_card/smart_card_permission_context.cc

@@ -55,11 +55,11 @@ class SmartCardPermissionContext::PowerSuspendObserver
  public:
   explicit PowerSuspendObserver(SmartCardPermissionContext& permission_context)
       : permission_context_(permission_context) {
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   }
 
   ~PowerSuspendObserver() override {
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   }
 
   void OnSuspend() override {

chrome/browser/ui/views/relaunch_notification/relaunch_notification_controller_unittest.cc

@@ -196,7 +196,7 @@ class RelaunchNotificationControllerTest : public ::testing::Test {
     // Unittests failed when the system is on battery. This class is using a
     // mock power monitor source `power_monitor_source_` to ensure no real
     // power state or power notifications are delivered to the unittests.
-    EXPECT_FALSE(base::PowerMonitor::IsOnBatteryPower());
+    EXPECT_FALSE(base::PowerMonitor::GetInstance()->IsOnBatteryPower());
   }
 
   UpgradeDetector* upgrade_detector() { return &upgrade_detector_; }

chrome/browser/ui/web_applications/web_app_metrics.cc

@@ -109,7 +109,7 @@ WebAppMetrics::WebAppMetrics(Profile* profile)
       icon_health_checks_(profile),
       browser_tab_strip_tracker_(this, nullptr) {
   browser_tab_strip_tracker_.Init();
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   BrowserList::AddObserver(this);
   // This isn't around on ChromeOS or tests.
   if (metrics::DesktopSessionDurationTracker::IsInitialized()) {
@@ -133,7 +133,7 @@ WebAppMetrics::WebAppMetrics(Profile* profile)
 
 WebAppMetrics::~WebAppMetrics() {
   BrowserList::RemoveObserver(this);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   if (metrics::DesktopSessionDurationTracker::IsInitialized()) {
     metrics::DesktopSessionDurationTracker::Get()->RemoveObserver(this);
   }

chrome/test/base/chrome_unit_test_suite.cc

@@ -87,7 +87,7 @@ class ChromeUnitTestSuiteInitializer : public testing::EmptyTestEventListener {
   void OnTestEnd(const testing::TestInfo& test_info) override {
     TestingBrowserProcess::TearDownAndDeleteInstance();
     // Some tests cause ChildThreadImpl to initialize a PowerMonitor.
-    base::PowerMonitor::ShutdownForTesting();
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
 #if BUILDFLAG(IS_WIN)
     // Running tests locally on Windows machines with some degree of
     // accessibility enabled can cause this flag to become implicitly set.

chromeos/ash/components/feature_usage/feature_usage_metrics.cc

@@ -65,7 +65,7 @@ FeatureUsageMetrics::FeatureUsageMetrics(const std::string& feature_name,
   // Schedule the first run some time in the future to not overload startup
   // flow.
   SetupTimer(kInitialInterval);
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 }
 
 void FeatureUsageMetrics::SetupTimer(base::TimeDelta delta) {
@@ -77,7 +77,7 @@ void FeatureUsageMetrics::SetupTimer(base::TimeDelta delta) {
 
 FeatureUsageMetrics::~FeatureUsageMetrics() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   MaybeReportUseTime();
 }
 

chromeos/ash/components/feature_usage/feature_usage_metrics_unittest.cc

@@ -31,8 +31,9 @@ class FeatureUsageMetricsTest : public ::testing::Test,
                                 public FeatureUsageMetrics::Delegate {
  public:
   FeatureUsageMetricsTest() {
-    if (!base::PowerMonitor::IsInitialized()) {
+    if (auto* power_monitor = base::PowerMonitor::GetInstance();
-      base::PowerMonitor::Initialize(
+        !power_monitor->IsInitialized()) {
+      power_monitor->Initialize(
           std::make_unique<base::PowerMonitorDeviceSource>());
     }
 

chromeos/ash/components/timezone/timezone_resolver.cc

@@ -269,7 +269,7 @@ TimeZoneResolver::TimeZoneResolverImpl::TimeZoneResolverImpl(
   DCHECK(!resolver_->apply_timezone().is_null());
   DCHECK(!resolver_->delay_network_call().is_null());
 
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 
   const int64_t last_refresh_at_us =
       resolver_->local_state()->GetInt64(kLastTimeZoneRefreshTime);
@@ -285,7 +285,7 @@ TimeZoneResolver::TimeZoneResolverImpl::TimeZoneResolverImpl(
 }
 
 TimeZoneResolver::TimeZoneResolverImpl::~TimeZoneResolverImpl() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 void TimeZoneResolver::TimeZoneResolverImpl::Start() {

chromeos/ash/services/multidevice_setup/wifi_sync_notification_controller.cc

@@ -80,7 +80,7 @@ WifiSyncNotificationController::WifiSyncNotificationController(
       delegate_notifier_(delegate_notifier) {
   if (pref_service_->GetBoolean(kCanShowWifiSyncAnnouncementPrefName)) {
     session_manager::SessionManager::Get()->AddObserver(this);
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
     did_register_session_observers_ = true;
   }
 }
@@ -88,7 +88,7 @@ WifiSyncNotificationController::WifiSyncNotificationController(
 WifiSyncNotificationController::~WifiSyncNotificationController() {
   if (did_register_session_observers_) {
     session_manager::SessionManager::Get()->RemoveObserver(this);
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   }
 }
 

chromeos/dbus/power/power_manager_client_unittest.cc

@@ -772,7 +772,7 @@ TEST_F(PowerManagerClientTest, ChangeAmbientColorTemperature) {
 TEST_F(PowerManagerClientTest, ChangeThermalState) {
   base::test::ScopedPowerMonitorTestSource power_monitor_source;
   PowerMonitorTestObserverLocal observer;
-  base::PowerMonitor::AddPowerThermalObserver(&observer);
+  base::PowerMonitor::GetInstance()->AddPowerThermalObserver(&observer);
 
   typedef struct {
     power_manager::ThermalEvent::ThermalState dbus_state;
@@ -810,7 +810,7 @@ TEST_F(PowerManagerClientTest, ChangeThermalState) {
     EXPECT_EQ(observer.GetThermalState(), p.expected_state);
   }
 
-  base::PowerMonitor::RemovePowerThermalObserver(&observer);
+  base::PowerMonitor::GetInstance()->RemovePowerThermalObserver(&observer);
 }
 
 // Test that |RequestSuspend| calls the DBus method with the same name.

components/download/internal/background_service/scheduler/battery_status_listener.h

@@ -24,7 +24,7 @@ class BatteryStatusListener {
   virtual int GetBatteryPercentage() = 0;
 
   // Is the device is using battery power instead of charging.
-  virtual bool IsOnBatteryPower() = 0;
+  virtual bool IsOnBatteryPower() const = 0;
 
   // Start/Stop to listen to battery status changes.
   virtual void Start(Observer* observer) = 0;

components/download/internal/background_service/scheduler/battery_status_listener_impl.cc

@@ -22,21 +22,22 @@ int BatteryStatusListenerImpl::GetBatteryPercentage() {
   return battery_percentage_;
 }
 
-bool BatteryStatusListenerImpl::IsOnBatteryPower() {
+bool BatteryStatusListenerImpl::IsOnBatteryPower() const {
-  return base::PowerMonitor::IsOnBatteryPower();
+  return base::PowerMonitor::GetInstance()->IsOnBatteryPower();
 }
 
 void BatteryStatusListenerImpl::Start(Observer* observer) {
   observer_ = observer;
 
-  DCHECK(base::PowerMonitor::IsInitialized());
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::AddPowerStateObserver(this);
+  DCHECK(power_monitor->IsInitialized());
+  power_monitor->AddPowerStateObserver(this);
 
   UpdateBatteryPercentage(true);
 }
 
 void BatteryStatusListenerImpl::Stop() {
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
 }
 
 int BatteryStatusListenerImpl::GetBatteryPercentageInternal() {

components/download/internal/background_service/scheduler/battery_status_listener_impl.h

@@ -33,7 +33,7 @@ class BatteryStatusListenerImpl : public BatteryStatusListener,
  private:
   // BatteryStatusListener implementation.
   int GetBatteryPercentage() override;
-  bool IsOnBatteryPower() override;
+  bool IsOnBatteryPower() const override;
   void Start(Observer* observer) override;
   void Stop() override;
 

components/download/internal/background_service/scheduler/battery_status_listener_mac.cc

@@ -14,7 +14,7 @@ int BatteryStatusListenerMac::GetBatteryPercentage() {
   return 100;
 }
 
-bool BatteryStatusListenerMac::IsOnBatteryPower() {
+bool BatteryStatusListenerMac::IsOnBatteryPower() const {
   return false;
 }
 

components/download/internal/background_service/scheduler/battery_status_listener_mac.h

@@ -25,7 +25,7 @@ class BatteryStatusListenerMac : public BatteryStatusListener {
  private:
   // BatteryStatusListener implementation.
   int GetBatteryPercentage() override;
-  bool IsOnBatteryPower() override;
+  bool IsOnBatteryPower() const override;
   void Start(Observer* observer) override;
   void Stop() override;
 };

components/nacl/loader/nacl_main.cc

@@ -31,7 +31,7 @@ int NaClMain(content::MainFunctionParams parameters) {
   base::SingleThreadTaskExecutor main_task_executor(base::MessagePumpType::IO);
   base::PlatformThread::SetName("CrNaClMain");
 
-  base::PowerMonitor::Initialize(MakePowerMonitorDeviceSource());
+  base::PowerMonitor::GetInstance()->Initialize(MakePowerMonitorDeviceSource());
   base::HighResolutionTimerManager hi_res_timer_manager;
 
 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)

components/power_monitor/power_monitor_device_source_linux.cc

@@ -47,7 +47,7 @@ PowerMonitorDeviceSourceLinux::~PowerMonitorDeviceSourceLinux() {
     ShutdownBus();
 }
 
-bool PowerMonitorDeviceSourceLinux::IsOnBatteryPower() {
+bool PowerMonitorDeviceSourceLinux::IsOnBatteryPower() const {
   // TODO(crbug.com/40836663): Use org.freedesktop.UPower to check for
   // OnBattery. One possibility is to connect to the DeviceService's
   // BatteryMonitor.

components/power_monitor/power_monitor_device_source_linux.h

@@ -27,7 +27,7 @@ class PowerMonitorDeviceSourceLinux : public base::PowerMonitorSource {
   ~PowerMonitorDeviceSourceLinux() override;
 
   // base::PowerMonitorSource:
-  bool IsOnBatteryPower() override;
+  bool IsOnBatteryPower() const override;
 
  private:
   void ShutdownBus();

components/viz/service/display/dc_layer_overlay.cc

@@ -813,8 +813,8 @@ DCLayerOverlayProcessor::DCLayerOverlayProcessor(
     : has_overlay_support_(skip_initialization_for_testing),
       allowed_yuv_overlay_count_(allowed_yuv_overlay_count),
       is_on_battery_power_(
-          base::PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(
+          base::PowerMonitor::GetInstance()
-              this)),
+              ->AddPowerStateObserverAndReturnOnBatteryState(this)),
       no_undamaged_overlay_promotion_(base::FeatureList::IsEnabled(
           features::kNoUndamagedOverlayPromotion)) {
   if (!skip_initialization_for_testing) {
@@ -829,7 +829,7 @@ DCLayerOverlayProcessor::DCLayerOverlayProcessor(
 
 DCLayerOverlayProcessor::~DCLayerOverlayProcessor() {
   gl::DirectCompositionOverlayCapsMonitor::GetInstance()->RemoveObserver(this);
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
 }
 
 void DCLayerOverlayProcessor::UpdateHasHwOverlaySupport() {

components/viz/service/main/viz_main_impl.cc

@@ -88,7 +88,7 @@ VizMainImpl::VizMainImpl(Delegate* delegate,
   // split into separate processes. Until then this is necessary to be able to
   // run Mushrome (chrome with mus) with Mus running in the browser process.
   if (dependencies_.power_monitor_source) {
-    base::PowerMonitor::Initialize(
+    base::PowerMonitor::GetInstance()->Initialize(
         std::move(dependencies_.power_monitor_source));
   }
 

components/viz/service/main/viz_main_impl_unittest.cc

@@ -74,7 +74,7 @@ class MockPowerMonitorSource : public base::PowerMonitorSource {
 
   ~MockPowerMonitorSource() override { *leak_guard_ = false; }
 
-  bool IsOnBatteryPower() override { return false; }
+  bool IsOnBatteryPower() const override { return false; }
 
  private:
   // An external flag to signal as to whether or not this object is still
@@ -129,8 +129,9 @@ TEST(VizMainImplTest, OopVizDependencyInjection) {
   builder.Record(recorder);
 
   // Need to shutdown the |PowerMonitor| infrastructure.
-  EXPECT_TRUE(base::PowerMonitor::IsInitialized());
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::ShutdownForTesting();
+  EXPECT_TRUE(power_monitor->IsInitialized());
+  power_monitor->ShutdownForTesting();
   // Double-check that we're not leaking the MockPowerMonitorSource
   // instance.
   ASSERT_FALSE(mock_source_is_alive);

content/app/content_main_runner_impl.cc

@@ -1248,7 +1248,8 @@ int ContentMainRunnerImpl::RunBrowser(MainFunctionParams main_params,
 
     // PowerMonitor is needed in reduced mode. BrowserMainLoop will safely skip
     // initializing it again if it has already been initialized.
-    base::PowerMonitor::Initialize(MakePowerMonitorDeviceSource());
+    base::PowerMonitor::GetInstance()->Initialize(
+        MakePowerMonitorDeviceSource());
 
     // Ensure the visibility tracker is created on the main thread.
     ProcessVisibilityTracker::GetInstance();

content/browser/android/battery_metrics.cc

@@ -182,9 +182,10 @@ AndroidBatteryMetrics::~AndroidBatteryMetrics() {
 
 void AndroidBatteryMetrics::InitializeOnSequence() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
   on_battery_power_ =
-      base::PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(this);
+      power_monitor->AddPowerStateObserverAndReturnOnBatteryState(this);
-  base::PowerMonitor::AddPowerThermalObserver(this);
+  power_monitor->AddPowerThermalObserver(this);
   content::ProcessVisibilityTracker::GetInstance()->AddObserver(this);
   // TODO(b/339859756): Update this call to take into account the unknown battery
   // status.
@@ -234,7 +235,7 @@ void AndroidBatteryMetrics::UpdateMetricsEnabled() {
   if (should_be_enabled && !metrics_timer_.IsRunning()) {
     // Capture first capacity measurement and enable the repeating timer.
     last_remaining_capacity_uah_ =
-        base::PowerMonitor::GetRemainingBatteryCapacity();
+        base::PowerMonitor::GetInstance()->GetRemainingBatteryCapacity();
     skipped_timers_ = 0;
     observed_capacity_drops_ = 0;
 
@@ -252,7 +253,7 @@ void AndroidBatteryMetrics::UpdateMetricsEnabled() {
 
 void AndroidBatteryMetrics::CaptureAndReportMetrics(bool disabling) {
   int remaining_capacity_uah =
-      base::PowerMonitor::GetRemainingBatteryCapacity();
+      base::PowerMonitor::GetInstance()->GetRemainingBatteryCapacity();
 
   if (remaining_capacity_uah >= last_remaining_capacity_uah_) {
     // No change in battery capacity, or it increased. The latter could happen

content/browser/browser_main_loop.cc

@@ -668,8 +668,10 @@ void BrowserMainLoop::PostCreateMainMessageLoop() {
   }
   {
     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:PowerMonitor");
-    if (!base::PowerMonitor::IsInitialized())
+    if (auto* power_monitor = base::PowerMonitor::GetInstance();
-      base::PowerMonitor::Initialize(MakePowerMonitorDeviceSource());
+        !power_monitor->IsInitialized()) {
+      power_monitor->Initialize(MakePowerMonitorDeviceSource());
+    }
   }
   {
     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:HighResTimerManager");

content/browser/media/browser_feature_provider.cc

@@ -51,8 +51,10 @@ void BrowserFeatureProvider::AddFeatures(FeatureVector features,
           static_cast<int>(net::NetworkChangeNotifier::GetConnectionType()));
     } else if (desc.name == FeatureLibrary::BatteryPower().name) {
       bool is_battery = false;
-      if (base::PowerMonitor::IsInitialized())
+      if (auto* power_monitor = base::PowerMonitor::GetInstance();
-        is_battery = base::PowerMonitor::IsOnBatteryPower();
+          power_monitor->IsInitialized()) {
+        is_battery = power_monitor->IsOnBatteryPower();
+      }
       features[i] = FeatureValue(is_battery);
     }
   }

content/browser/renderer_host/media/media_stream_power_logger.cc

@@ -17,13 +17,15 @@ void SendLogMessage(const std::string& message) {
 }  // namespace
 
 MediaStreamPowerLogger::MediaStreamPowerLogger() {
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::AddPowerThermalObserver(this);
+  power_monitor->AddPowerSuspendObserver(this);
+  power_monitor->AddPowerThermalObserver(this);
 }
 
 MediaStreamPowerLogger::~MediaStreamPowerLogger() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::RemovePowerThermalObserver(this);
+  power_monitor->RemovePowerSuspendObserver(this);
+  power_monitor->RemovePowerThermalObserver(this);
 }
 
 void MediaStreamPowerLogger::OnSuspend() {

content/browser/renderer_host/media/peer_connection_tracker_host.cc

@@ -75,10 +75,11 @@ PeerConnectionTrackerHost::PeerConnectionTrackerHost(RenderFrameHost* frame)
       peer_pid_(frame->GetProcess()->GetProcess().Pid()) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   RegisterHost(this);
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
+  power_monitor->AddPowerSuspendObserver(this);
   // Ensure that the initial thermal state is known by the |tracker_|.
   base::PowerThermalObserver::DeviceThermalState initial_thermal_state =
-      base::PowerMonitor::AddPowerStateObserverAndReturnPowerThermalState(this);
+      power_monitor->AddPowerStateObserverAndReturnPowerThermalState(this);
 
   frame->GetRemoteInterfaces()->GetInterface(
       tracker_.BindNewPipeAndPassReceiver());
@@ -91,8 +92,9 @@ PeerConnectionTrackerHost::PeerConnectionTrackerHost(RenderFrameHost* frame)
 PeerConnectionTrackerHost::~PeerConnectionTrackerHost() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   RemoveHost(this);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::RemovePowerThermalObserver(this);
+  power_monitor->RemovePowerSuspendObserver(this);
+  power_monitor->RemovePowerThermalObserver(this);
 }
 
 void PeerConnectionTrackerHost::AddPeerConnection(

content/child/child_thread_impl.cc

@@ -706,12 +706,13 @@ void ChildThreadImpl::Init(const Options& options) {
   }
 
   // In single process mode we may already have initialized the power monitor,
-  if (!base::PowerMonitor::IsInitialized()) {
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
+      !power_monitor->IsInitialized()) {
     auto power_monitor_source =
         std::make_unique<device::PowerMonitorBroadcastSource>(
             GetIOTaskRunner());
     auto* source_ptr = power_monitor_source.get();
-    base::PowerMonitor::Initialize(std::move(power_monitor_source));
+    power_monitor->Initialize(std::move(power_monitor_source));
     // The two-phase init is necessary to ensure that the process-wide
     // PowerMonitor is set before the power monitor source receives incoming
     // communication from the browser process (see https://crbug.com/821790 for

content/gpu/gpu_child_thread.cc

@@ -84,7 +84,7 @@ ChildThreadImpl::Options GetOptions(
 
 viz::VizMainImpl::ExternalDependencies CreateVizMainDependencies() {
   viz::VizMainImpl::ExternalDependencies deps;
-  if (!base::PowerMonitor::IsInitialized()) {
+  if (!base::PowerMonitor::GetInstance()->IsInitialized()) {
     deps.power_monitor_source =
         std::make_unique<base::PowerMonitorDeviceSource>();
   }

content/shell/common/power_monitor_test_impl.cc

@@ -20,11 +20,11 @@ void PowerMonitorTestImpl::MakeSelfOwnedReceiver(
 }
 
 PowerMonitorTestImpl::PowerMonitorTestImpl() {
-  base::PowerMonitor::AddPowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerStateObserver(this);
 }
 
 PowerMonitorTestImpl::~PowerMonitorTestImpl() {
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
 }
 
 void PowerMonitorTestImpl::QueryNextState(QueryNextStateCallback callback) {

content/utility/utility_main.cc

@@ -388,7 +388,7 @@ int UtilityMain(MainFunctionParams parameters) {
   // base::HighResolutionTimerManager here for future possible usage of high
   // resolution timer in service utility process.
   std::optional<base::HighResolutionTimerManager> hi_res_timer_manager;
-  if (base::PowerMonitor::IsInitialized()) {
+  if (base::PowerMonitor::GetInstance()->IsInitialized()) {
     hi_res_timer_manager.emplace();
   }
 

google_apis/gcm/engine/heartbeat_manager.cc

@@ -62,7 +62,7 @@ HeartbeatManager::HeartbeatManager(
 
 HeartbeatManager::~HeartbeatManager() {
   // Stop listening for system suspend and resume events.
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 void HeartbeatManager::Start(
@@ -74,7 +74,7 @@ void HeartbeatManager::Start(
   trigger_reconnect_callback_ = trigger_reconnect_callback;
 
   // Listen for system suspend and resume events.
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 
   // Calculated the heartbeat interval just before we start the timer.
   UpdateHeartbeatInterval();
@@ -90,7 +90,7 @@ void HeartbeatManager::Stop() {
   heartbeat_timer_->Stop();
   waiting_for_ack_ = false;
 
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 void HeartbeatManager::OnHeartbeatAcked() {

gpu/command_buffer/service/webgpu_decoder_impl.cc

@@ -1628,8 +1628,9 @@ wgpu::Adapter WebGPUDecoderImpl::CreatePreferredAdapter(
     case WebGPUPowerPreference::kNone:
       if (power_preference == wgpu::PowerPreference::Undefined) {
         // If on battery power, default to the integrated GPU.
-        if (!base::PowerMonitor::IsInitialized() ||
+        if (auto* power_monitor = base::PowerMonitor::GetInstance();
-            base::PowerMonitor::IsOnBatteryPower()) {
+            !power_monitor->IsInitialized() ||
+            power_monitor->IsOnBatteryPower()) {
           power_preference = wgpu::PowerPreference::LowPower;
         } else {
           power_preference = wgpu::PowerPreference::HighPerformance;

gpu/ipc/service/dcomp_texture_win.cc

@@ -127,7 +127,7 @@ DCOMPTexture::DCOMPTexture(
   IPC::ScopedAllowOffSequenceChannelAssociatedBindings allow_binding;
   receiver_.Bind(std::move(receiver), runner);
   context_state_->AddContextLostObserver(this);
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   channel_->AddRoute(route_id, sequence_);
 }
 
@@ -138,7 +138,7 @@ DCOMPTexture::~DCOMPTexture() {
   DCHECK(!channel_);
 
   context_state_->RemoveContextLostObserver(this);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 
   if (window_pos_timer_.IsRunning()) {
     window_pos_timer_.Stop();

gpu/ipc/service/gpu_watchdog_thread.cc

@@ -127,7 +127,7 @@ GpuWatchdogThread::~GpuWatchdogThread() {
   Stop();  // stop the watchdog thread
 
   base::CurrentThread::Get()->RemoveTaskObserver(this);
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   GpuWatchdogThreadEventHistogram(GpuWatchdogThreadEvent::kGpuWatchdogEnd);
 #if BUILDFLAG(IS_WIN)
   if (watched_thread_handle_)
@@ -343,7 +343,8 @@ void GpuWatchdogThread::AddPowerObserver() {
   // Adding the Observer to the power monitor is safe even if power monitor is
   // not yet initialized.
   bool is_system_suspended =
-      base::PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(this);
+      base::PowerMonitor::GetInstance()
+          ->AddPowerSuspendObserverAndReturnSuspendedState(this);
   if (is_system_suspended)
     StopWatchdogTimeoutTask(kPowerSuspendResume);
 }

ios/web/init/web_main_loop.mm

@@ -115,7 +115,7 @@ int WebMainLoop::PreCreateThreads() {
   // of it?
   // TODO(crbug.com/40240952): Remove this once we have confidence PowerMonitor
   // is not needed for iOS
-  base::PowerMonitor::Initialize(
+  base::PowerMonitor::GetInstance()->Initialize(
       std::make_unique<base::PowerMonitorDeviceSource>());
 
   return result_code_;

media/audio/mac/audio_manager_mac.cc

@@ -462,7 +462,7 @@ class AudioManagerMac::AudioPowerObserver : public base::PowerSuspendObserver {
  public:
   AudioPowerObserver()
       : is_suspending_(false),
-        is_monitoring_(base::PowerMonitor::IsInitialized()),
+        is_monitoring_(base::PowerMonitor::GetInstance()->IsInitialized()),
         num_resume_notifications_(0) {
     // The PowerMonitor requires significant setup (a CFRunLoop and preallocated
     // IO ports) so it's not available under unit tests.  See the OSX impl of
@@ -470,7 +470,7 @@ class AudioManagerMac::AudioPowerObserver : public base::PowerSuspendObserver {
     if (!is_monitoring_) {
       return;
     }
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   }
 
   AudioPowerObserver(const AudioPowerObserver&) = delete;
@@ -481,7 +481,7 @@ class AudioManagerMac::AudioPowerObserver : public base::PowerSuspendObserver {
     if (!is_monitoring_) {
       return;
     }
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   }
 
   bool IsSuspending() const {
@@ -500,7 +500,7 @@ class AudioManagerMac::AudioPowerObserver : public base::PowerSuspendObserver {
 
   bool IsOnBatteryPower() const {
     DCHECK(thread_checker_.CalledOnValidThread());
-    return base::PowerMonitor::IsOnBatteryPower();
+    return base::PowerMonitor::GetInstance()->IsOnBatteryPower();
   }
 
  private:

media/audio/power_observer_helper.cc

@@ -29,12 +29,12 @@ PowerObserverHelper::PowerObserverHelper(
   // TODO(grunell): We could be suspending when adding this as observer, and
   // we won't be notified about that. See if we can add
   // PowerMonitorSource::IsSuspending() so that this can be checked here.
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 }
 
 PowerObserverHelper::~PowerObserverHelper() {
   DCHECK(task_runner_->RunsTasksInCurrentSequence());
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 }
 
 bool PowerObserverHelper::IsSuspending() const {

media/renderers/audio_renderer_impl.cc

@@ -83,14 +83,16 @@ AudioRendererImpl::AudioRendererImpl(
   // won't remove the observer until we're destructed on |task_runner_| so we
   // must post it here if we're on the wrong thread.
   if (task_runner_->RunsTasksInCurrentSequence()) {
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->GetInstance()->AddPowerSuspendObserver(
+        this);
   } else {
     // Safe to post this without a WeakPtr because this class must be destructed
     // on the same thread and construction has not completed yet.
     task_runner_->PostTask(
         FROM_HERE,
         base::BindOnce(
-            IgnoreResult(&base::PowerMonitor::AddPowerSuspendObserver), this));
+            base::IgnoreResult(&base::PowerMonitor::AddPowerSuspendObserver),
+            base::Unretained(base::PowerMonitor::GetInstance()), this));
   }
 
   // Do not add anything below this line since the above actions are only safe
@@ -100,7 +102,8 @@ AudioRendererImpl::AudioRendererImpl(
 AudioRendererImpl::~AudioRendererImpl() {
   DVLOG(1) << __func__;
   DCHECK(task_runner_->RunsTasksInCurrentSequence());
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->GetInstance()->RemovePowerSuspendObserver(
+      this);
 
   // If Render() is in progress, this call will wait for Render() to finish.
   // After this call, the |sink_| will not call back into |this| anymore.

net/http/http_cache_transaction.cc

@@ -91,10 +91,8 @@ bool NonErrorResponse(int status_code) {
 }
 
 bool IsOnBatteryPower() {
-  if (base::PowerMonitor::IsInitialized()) {
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-    return base::PowerMonitor::IsOnBatteryPower();
+  return power_monitor->IsInitialized() && power_monitor->IsOnBatteryPower();
-  }
-  return false;
 }
 
 enum ExternallyConditionalizedType {

net/http/http_network_layer.cc

@@ -26,14 +26,14 @@ HttpNetworkLayer::HttpNetworkLayer(HttpNetworkSession* session)
     : session_(session) {
   DCHECK(session_);
 #if BUILDFLAG(IS_WIN)
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 #endif
 }
 
 HttpNetworkLayer::~HttpNetworkLayer() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
 #if BUILDFLAG(IS_WIN)
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 #endif
 }
 

net/socket/tcp_client_socket.cc

@@ -73,7 +73,7 @@ TCPClientSocket::TCPClientSocket(
 TCPClientSocket::~TCPClientSocket() {
   Disconnect();
 #if defined(TCP_CLIENT_SOCKET_OBSERVES_SUSPEND)
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
 #endif  // defined(TCP_CLIENT_SOCKET_OBSERVES_SUSPEND)
 }
 
@@ -173,7 +173,7 @@ TCPClientSocket::TCPClientSocket(
   if (socket_->IsValid())
     socket_->SetDefaultOptionsForClient();
 #if defined(TCP_CLIENT_SOCKET_OBSERVES_SUSPEND)
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
 #endif  // defined(TCP_CLIENT_SOCKET_OBSERVES_SUSPEND)
 }
 

net/socket/tcp_client_socket_unittest.cc

@@ -60,7 +60,9 @@ class TCPClientSocketTest : public testing::Test {
   TCPClientSocketTest()
       : task_environment_(base::test::TaskEnvironment::MainThreadType::IO) {}
 
-  ~TCPClientSocketTest() override { base::PowerMonitor::ShutdownForTesting(); }
+  ~TCPClientSocketTest() override {
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
+  }
 
   void Suspend() { power_monitor_source_.Suspend(); }
   void Resume() { power_monitor_source_.Resume(); }

services/device/power_monitor/power_monitor_message_broadcaster.cc

@@ -10,13 +10,15 @@
 namespace device {
 
 PowerMonitorMessageBroadcaster::PowerMonitorMessageBroadcaster() {
-  base::PowerMonitor::AddPowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::AddPowerStateObserver(this);
+  power_monitor->AddPowerSuspendObserver(this);
+  power_monitor->AddPowerStateObserver(this);
 }
 
 PowerMonitorMessageBroadcaster::~PowerMonitorMessageBroadcaster() {
-  base::PowerMonitor::RemovePowerSuspendObserver(this);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  power_monitor->RemovePowerSuspendObserver(this);
+  power_monitor->RemovePowerStateObserver(this);
 }
 
 // static
@@ -30,11 +32,13 @@ void PowerMonitorMessageBroadcaster::AddClient(
         power_monitor_client) {
   mojo::RemoteSetElementId element_id =
       clients_.Add(std::move(power_monitor_client));
+  auto* power_monitor = base::PowerMonitor::GetInstance();
 
-  if (!base::PowerMonitor::IsInitialized())
+  if (!power_monitor->IsInitialized()) {
     return;
+  }
 
-  bool on_battery_power = base::PowerMonitor::IsOnBatteryPower();
+  bool on_battery_power = power_monitor->IsOnBatteryPower();
 
   // If the state has changed since we last checked, update all clients.
   if (on_battery_power != on_battery_power_) {

services/device/power_monitor/power_monitor_message_broadcaster_unittest.cc

@@ -62,7 +62,9 @@ class PowerMonitorMessageBroadcasterTest : public DeviceServiceTestBase {
     power_monitor_source_.SetOnBatteryPower(on_battery_power);
   }
 
-  bool IsOnBatteryPower() { return power_monitor_source_.IsOnBatteryPower(); }
+  bool IsOnBatteryPower() const {
+    return power_monitor_source_.IsOnBatteryPower();
+  }
 
   void TearDown() override {
     DestroyDeviceService();

services/device/public/cpp/power_monitor/power_monitor_broadcast_source.cc

@@ -35,7 +35,7 @@ void PowerMonitorBroadcastSource::Init(
   }
 }
 
-bool PowerMonitorBroadcastSource::IsOnBatteryPower() {
+bool PowerMonitorBroadcastSource::IsOnBatteryPower() const {
   return client_->last_reported_on_battery_power_state();
 }
 

services/device/public/cpp/power_monitor/power_monitor_broadcast_source.h

@@ -85,7 +85,7 @@ class PowerMonitorBroadcastSource : public base::PowerMonitorSource {
 
   Client* client_for_testing() const { return client_.get(); }
 
-  bool IsOnBatteryPower() override;
+  bool IsOnBatteryPower() const override;
 
   std::unique_ptr<Client> client_;
   scoped_refptr<base::SequencedTaskRunner> task_runner_;

services/device/public/cpp/power_monitor/power_monitor_broadcast_source_unittest.cc

@@ -29,12 +29,13 @@ class PowerMonitorBroadcastSourceTest : public testing::Test {
     auto power_monitor_source = std::make_unique<PowerMonitorBroadcastSource>(
         base::SequencedTaskRunner::GetCurrentDefault());
     power_monitor_source_ptr_ = power_monitor_source.get();
-    base::PowerMonitor::Initialize(std::move(power_monitor_source));
+    base::PowerMonitor::GetInstance()->Initialize(
+        std::move(power_monitor_source));
     power_monitor_source_ptr_->Init(mojo::NullRemote());
   }
 
   void TearDown() override {
-    base::PowerMonitor::ShutdownForTesting();
+    base::PowerMonitor::GetInstance()->ShutdownForTesting();
     base::RunLoop().RunUntilIdle();
   }
 
@@ -51,8 +52,9 @@ class PowerMonitorBroadcastSourceTest : public testing::Test {
 
 TEST_F(PowerMonitorBroadcastSourceTest, PowerMessageReceiveBroadcast) {
   base::test::PowerMonitorTestObserver observer;
-  base::PowerMonitor::AddPowerSuspendObserver(&observer);
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-  base::PowerMonitor::AddPowerStateObserver(&observer);
+  power_monitor->AddPowerSuspendObserver(&observer);
+  power_monitor->AddPowerStateObserver(&observer);
 
   // Sending resume when not suspended should have no effect.
   client()->Resume();
@@ -103,8 +105,8 @@ TEST_F(PowerMonitorBroadcastSourceTest, PowerMessageReceiveBroadcast) {
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(observer.power_state_changes(), 2);
 
-  base::PowerMonitor::RemovePowerSuspendObserver(&observer);
+  power_monitor->RemovePowerSuspendObserver(&observer);
-  base::PowerMonitor::RemovePowerStateObserver(&observer);
+  power_monitor->RemovePowerStateObserver(&observer);
 }
 
 }  // namespace device

services/media_session/audio_focus_manager.cc

@@ -39,14 +39,14 @@ class MediaPowerDelegate : public base::PowerSuspendObserver {
  public:
   explicit MediaPowerDelegate(base::WeakPtr<AudioFocusManager> owner)
       : owner_(owner) {
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->AddPowerSuspendObserver(this);
   }
 
   MediaPowerDelegate(const MediaPowerDelegate&) = delete;
   MediaPowerDelegate& operator=(const MediaPowerDelegate&) = delete;
 
   ~MediaPowerDelegate() override {
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+    base::PowerMonitor::GetInstance()->RemovePowerSuspendObserver(this);
   }
 
   // base::PowerSuspendObserver:

third_party/blink/common/media/watch_time_reporter.cc

@@ -21,9 +21,8 @@ namespace blink {
 constexpr gfx::Size kMinimumVideoSize = gfx::Size(200, 140);
 
 static bool IsOnBatteryPower() {
-  if (base::PowerMonitor::IsInitialized())
+  auto* power_monitor = base::PowerMonitor::GetInstance();
-    return base::PowerMonitor::IsOnBatteryPower();
+  return power_monitor->IsInitialized() && power_monitor->IsOnBatteryPower();
-  return false;
 }
 
 // Helper function for managing property changes. If the watch time timer is
@@ -96,7 +95,7 @@ WatchTimeReporter::WatchTimeReporter(
   if (is_muted_)
     DCHECK_EQ(volume_, 1.0);
 
-  base::PowerMonitor::AddPowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->AddPowerStateObserver(this);
 
   provider->AcquireWatchTimeRecorder(properties_->Clone(),
                                      recorder_.BindNewPipeAndPassReceiver());
@@ -146,7 +145,7 @@ WatchTimeReporter::~WatchTimeReporter() {
   // This is our last chance, so finalize now if there's anything remaining.
   in_shutdown_ = true;
   MaybeFinalizeWatchTime(FinalizeTime::IMMEDIATELY);
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
 }
 
 void WatchTimeReporter::OnPlaying() {

third_party/blink/tools/blinkpy/presubmit/audit_non_blink_usage.py

@@ -39,56 +39,70 @@ _CONFIG = [
         'allowed': [
             # absl
             'absl::Cleanup',
-            'absl::MakeInt128',
-            'absl::MakeUint128',
-            'absl::Int128High64',
-            'absl::Int128Low64',
-            'absl::Uint128High64',
-            'absl::Uint128Low64',
             'absl::get',
             'absl::get_if',
             'absl::holds_alternative',
             'absl::in_place',
             'absl::in_place_type',
             'absl::int128',
+            'absl::Int128High64',
+            'absl::Int128Low64',
+            'absl::MakeInt128',
+            'absl::MakeUint128',
             'absl::monostate',
             'absl::uint128',
+            'absl::Uint128High64',
+            'absl::Uint128Low64',
             'absl::variant',
             'absl::visit',
 
             # //base constructs that are allowed everywhere
+            'base::(byte_)?span_from_ref',
             'base::AdoptRef',
             'base::ApplyMetadataToPastSamples',
-            'base::SampleMetadataScope',
+            'base::as_byte_span',
+            'base::as_byte_span',
+            'base::as_bytes',
+            'base::as_bytes',
+            'base::as_chars',
+            'base::as_chars',
+            'base::as_string_view',
+            'base::as_string_view',
+            'base::as_writable_byte_span',
+            'base::as_writable_bytes',
+            'base::as_writable_bytes',
+            'base::as_writable_chars',
             'base::AutoReset',
-            'base::Contains',
+            'base::bit_cast',
             'base::ConditionVariable',
+            'base::Contains',
             'base::CPU',
-            'base::ValuesEquivalent',
             'base::Days',
             'base::DefaultTickClock',
             'base::ElapsedTimer',
             'base::EnumSet',
-            'base::HashInts',
+            'base::expected',
-            'base::JobDelegate',
-            'base::JobHandle',
-            'base::PostJob',
             'base::File',
             'base::FileErrorOr',
             'base::FilePath',
             'base::FunctionRef',
             'base::GetUniqueIdForProcess',
+            'base::HashingLRUCache',
+            'base::HashInts',
             'base::HeapArray',
             'base::HexStringToUInt64',
             'base::Hours',
-            "base::i18n::TextDirection",
+            'base::i18n::TextDirection',
-            "base::i18n::ToChar16Ptr",
+            'base::i18n::ToChar16Ptr',
-            "base::i18n::ToUCharPtr",
+            'base::i18n::ToUCharPtr',
+            'base::JobDelegate',
+            'base::JobHandle',
             'base::Location',
+            'base::make_span',
             'base::MakeRefCounted',
             'base::MappedReadOnlyRegion',
-            'base::MatchPattern',
             'base::MatcherStringPattern',
+            'base::MatchPattern',
             'base::MessagePump',
             'base::MetricsSubSampler',
             'base::Microseconds',
@@ -96,6 +110,7 @@ _CONFIG = [
             'base::Minutes',
             'base::Nanoseconds',
             'base::NotFatalUntil',
+            'base::optional_ref',
             'base::OptionalFromPtr',
             'base::OptionalToPtr',
             'base::Overloaded',
@@ -103,21 +118,28 @@ _CONFIG = [
             'base::PersistentHash',
             'base::PlatformThread',
             'base::PlatformThreadId',
+            'base::PostJob',
+            'base::PowerMonitor',
             'base::Process',
             'base::RadToDeg',
-            'base::RefCountedData',
+            'base::ranges::.+',
-            'base::RunLoop',
-            'base::HashingLRUCache',
             'base::ReadOnlySharedMemoryMapping',
             'base::ReadOnlySharedMemoryRegion',
+            'base::RefCountedData',
             'base::RemoveChars',
             'base::RepeatingTimer',
+            'base::RunLoop',
+            'base::SampleMetadataScope',
+            'base::ScopedAllowBlocking',
+            'base::ScopedClosureRunner',
+            'base::ScopedFD',
             'base::Seconds',
+            'base::sequence_manager::TaskTimeObserver',
             'base::SequencedTaskRunner',
             'base::SingleThreadTaskRunner',
-            'base::ScopedAllowBlocking',
+            'base::span',
-            'base::ScopedFD',
+            'base::span(_with_nul)?_from_cstring',
-            'base::ScopedClosureRunner',
+            'base::Span(OrSize|Reader|Writer)',
             'base::StringPiece',
             'base::SubstringSetMatcher',
             'base::SupportsWeakPtr',
@@ -129,41 +151,20 @@ _CONFIG = [
             'base::Time',
             'base::TimeDelta',
             'base::TimeTicks',
-            'base::trace_event::.*',
+            'base::to_underlying',
             'base::Token',
+            'base::trace_event::.*',
+            'base::unexpected',
             'base::UnguessableToken',
             'base::UnguessableTokenHash',
             'base::UnlocalizedTimeFormatWithPattern',
             'base::UnsafeSharedMemoryRegion',
             'base::Uuid',
+            'base::ValuesEquivalent',
             'base::WeakPtr',
             'base::WeakPtrFactory',
             'base::WrapRefCounted',
             'base::WritableSharedMemoryMapping',
-            'base::as_byte_span',
-            'base::as_bytes',
-            'base::as_chars',
-            'base::as_string_view',
-            'base::as_writable_bytes',
-            'base::bit_cast',
-            'base::expected',
-            'base::make_span',
-            'base::optional_ref',
-            'base::to_underlying',
-            'base::unexpected',
-            'base::ranges::.+',
-            'base::sequence_manager::TaskTimeObserver',
-            'base::span',
-            'base::span(_with_nul)?_from_cstring',
-            'base::Span(OrSize|Reader|Writer)',
-            'base::as_byte_span',
-            'base::as_writable_byte_span',
-            'base::as_bytes',
-            'base::as_writable_bytes',
-            'base::as_chars',
-            'base::as_writable_chars',
-            'base::as_string_view',
-            'base::(byte_)?span_from_ref',
             'logging::GetVlogLevel',
             'logging::SetLogItems',
 
@@ -182,8 +183,8 @@ _CONFIG = [
             'base::bits::.+',
 
             # //base/observer_list.h.
-            'base::ObserverList',
             'base::CheckedObserver',
+            'base::ObserverList',
 
             # //base/functional/callback_helpers.h.
             'base::DoNothing',
@@ -222,60 +223,60 @@ _CONFIG = [
             'base::LinearHistogram',
 
             # //base/metrics/field_trial_params.h.
-            'base::GetFieldTrialParamValueByFeature',
             'base::GetFieldTrialParamByFeatureAsBool',
             'base::GetFieldTrialParamByFeatureAsDouble',
             'base::GetFieldTrialParamByFeatureAsInt',
+            'base::GetFieldTrialParamValueByFeature',
 
             # //base/numerics/safe_conversions.h.
             'base::as_signed',
             'base::as_unsigned',
             'base::checked_cast',
-            'base::saturated_cast',
-            'base::strict_cast',
             'base::ClampCeil',
             'base::ClampFloor',
+            'base::ClampRound',
             'base::IsTypeInRangeForNumericType',
             'base::IsValueInRangeForNumericType',
             'base::IsValueNegative',
             'base::MakeStrictNum',
-            'base::ClampRound',
             'base::SafeUnsignedAbs',
+            'base::saturated_cast',
+            'base::strict_cast',
             'base::StrictNumeric',
 
             # //base/synchronization/lock.h.
             'base::AutoLock',
-            'base::AutoUnlock',
             'base::AutoTryLock',
+            'base::AutoUnlock',
             'base::Lock',
 
             # //base/synchronization/waitable_event.h.
             'base::WaitableEvent',
 
             # //base/numerics/checked_math.h.
+            'base::CheckAdd',
+            'base::CheckAnd',
+            'base::CheckDiv',
             'base::CheckedNumeric',
-            'base::IsValidForType',
+            'base::CheckLsh',
-            'base::ValueOrDieForType',
-            'base::ValueOrDefaultForType',
-            'base::MakeCheckedNum',
             'base::CheckMax',
             'base::CheckMin',
-            'base::CheckAdd',
-            'base::CheckSub',
-            'base::CheckMul',
-            'base::CheckDiv',
             'base::CheckMod',
-            'base::CheckLsh',
+            'base::CheckMul',
-            'base::CheckRsh',
-            'base::CheckAnd',
             'base::CheckOr',
+            'base::CheckRsh',
+            'base::CheckSub',
             'base::CheckXor',
+            'base::IsValidForType',
+            'base::MakeCheckedNum',
+            'base::ValueOrDefaultForType',
+            'base::ValueOrDieForType',
 
             # //base/numerics/clamped_math.h.
             'base::ClampAdd',
             'base::ClampedNumeric',
-            'base::ClampMin',
             'base::ClampMax',
+            'base::ClampMin',
             'base::ClampSub',
             'base::MakeClampedNum',
 
@@ -291,32 +292,32 @@ _CONFIG = [
             'base::AtomicSequenceNumber',
 
             # Task traits
-            'base::TaskTraits',
             'base::MayBlock',
+            'base::SingleThreadTaskRunnerThreadMode',
             'base::TaskPriority',
             'base::TaskShutdownBehavior',
-            'base::WithBaseSyncPrimitives',
+            'base::TaskTraits',
             'base::ThreadPolicy',
             'base::ThreadPool',
-            'base::SingleThreadTaskRunnerThreadMode',
+            'base::WithBaseSyncPrimitives',
 
             # Byte order
-            'base::BigEndian(Reader|Writer)',
             'base::(numerics::)?((I|U)(8|16|32|64)|(Float|Double))(To|From)(Big|Little|Native)Endian',
             'base::(numerics::)?ByteSwap',
+            'base::BigEndian(Reader|Writer)',
 
             # (Cryptographic) random number generation
-            'base::RandUint64',
-            'base::RandInt',
-            'base::RandGenerator',
-            'base::RandDouble',
             'base::RandBytes',
             'base::RandBytesAsString',
+            'base::RandDouble',
+            'base::RandGenerator',
+            'base::RandInt',
+            'base::RandUint64',
 
             # Feature list checking.
+            "base::GetFieldTrial.*",
             'base::Feature.*',
             'base::FEATURE_.+',
-            "base::GetFieldTrial.*",
             'base::features::.+',
             'features::.+',
 
@@ -385,9 +386,9 @@ _CONFIG = [
             'partition_alloc::internal::kAlignment',
 
             # PartitionAlloc
-            'base::PartitionFree',
-            'base::PartitionAllocZeroFill',
             'base::PartitionAllocReturnNull',
+            'base::PartitionAllocZeroFill',
+            'base::PartitionFree',
 
             # For TaskObserver.
             'base::PendingTask',
@@ -397,20 +398,20 @@ _CONFIG = [
             'cc::CategorizedWorkerPool',
             'cc::ColorFilter',
             'cc::DrawLooper',
-            'cc::PathEffect',
             'cc::InspectablePaintRecorder',
             'cc::InspectableRecordPaintCanvas',
+            'cc::NodeId',
+            'cc::NodeInfo',
             'cc::PaintCanvas',
             'cc::PaintFlags',
             'cc::PaintImage',
             'cc::PaintImageBuilder',
             'cc::PaintRecord',
-            'cc::RecordPaintCanvas',
             'cc::PaintShader',
             'cc::PaintWorkletInput',
+            'cc::PathEffect',
+            'cc::RecordPaintCanvas',
             'cc::RefCountedBuffer',
-            'cc::NodeId',
-            'cc::NodeInfo',
             'cc::UsePaintCache',
 
             # Chromium geometry types.
@@ -420,8 +421,8 @@ _CONFIG = [
             'gfx::Outsets',
             'gfx::OutsetsF',
             'gfx::Point',
-            'gfx::PointF',
             'gfx::Point3F',
+            'gfx::PointF',
             'gfx::QuadF',
             'gfx::Quaternion',
             'gfx::Rect',
@@ -443,25 +444,25 @@ _CONFIG = [
             'gfx::DotProduct',
             'gfx::IntersectRects',
             'gfx::MapRect',
+            'gfx::MapRect',
+            'gfx::MaximumCoveredRect',
             'gfx::PointAtOffsetFromOrigin',
             'gfx::PointFToSkPoint',
             'gfx::PointToSkIPoint',
-            'gfx::MapRect',
-            'gfx::MaximumCoveredRect',
             'gfx::RectFToSkRect',
             'gfx::RectToSkIRect',
             'gfx::RectToSkRect',
             'gfx::ScaleInsets',
+            'gfx::ScalePoint',
+            'gfx::ScaleRect',
+            'gfx::ScaleSize',
             'gfx::ScaleToCeiledSize',
             'gfx::ScaleToEnclosedRect',
             'gfx::ScaleToEnclosingRect',
             'gfx::ScaleToFlooredSize',
+            'gfx::ScaleToRoundedPoint',
             'gfx::ScaleToRoundedRect',
             'gfx::ScaleToRoundedSize',
-            'gfx::ScaleRect',
-            'gfx::ScaleSize',
-            'gfx::ScalePoint',
-            'gfx::ScaleToRoundedPoint',
             'gfx::ScaleVector2d',
             'gfx::ScaleVector3d',
             'gfx::SizeFToSkSize',
@@ -534,17 +535,17 @@ _CONFIG = [
             'cc::ViewportLayers',
 
             # cc::Layer helper enums.
-            'cc::HORIZONTAL',
-            'cc::VERTICAL',
-            'cc::THUMB',
-            'cc::TRACK_BUTTONS_TICKMARKS',
             'cc::BrowserControlsState',
             'cc::EventListenerClass',
             'cc::EventListenerProperties',
             'cc::HitTestOpaqueness',
+            'cc::HORIZONTAL',
+            'cc::THUMB',
+            'cc::TRACK_BUTTONS_TICKMARKS',
+            'cc::VERTICAL',
 
             # Animation
-            'cc::AnimationHost',
+            "cc::AnimationHost",
             "cc::AnimationIdProvider",
             "cc::AnimationTimeline",
             "cc::FilterKeyframe",
@@ -568,30 +569,30 @@ _CONFIG = [
             'cc::PaintHoldingReason',
 
             # Scrolling
+            'cc::BrowserControlsOffsetTagsInfo',
+            'cc::kManipulationInfoNone',
             'cc::kManipulationInfoPinchZoom',
             'cc::kManipulationInfoPrecisionTouchPad',
+            'cc::kManipulationInfoScrollbar',
             'cc::kManipulationInfoTouch',
             'cc::kManipulationInfoWheel',
-            'cc::kManipulationInfoScrollbar',
-            'cc::kManipulationInfoNone',
-            'cc::kPixelsPerLineStep',
             'cc::kMinFractionToStepWhenPaging',
             'cc::kPercentDeltaForDirectionalScroll',
-            'cc::BrowserControlsOffsetTagsInfo',
+            'cc::kPixelsPerLineStep',
             'cc::MainThreadScrollingReason',
             'cc::ManipulationInfo',
+            'cc::ScrollOffsetAnimationCurve',
             'cc::ScrollSnapAlign',
             'cc::ScrollSnapType',
-            'cc::ScrollOffsetAnimationCurve',
             'cc::ScrollStateData',
             'cc::ScrollUtils',
             'cc::SnapAlignment',
             'cc::SnapAreaData',
             'cc::SnapAxis',
             'cc::SnapContainerData',
-            'cc::SnappedTargetData',
             'cc::SnapFlingClient',
             'cc::SnapFlingController',
+            'cc::SnappedTargetData',
             'cc::SnapPositionData',
             'cc::SnapSelectionStrategy',
             'cc::SnapStrictness',
@@ -618,6 +619,7 @@ _CONFIG = [
             'url::.+',
 
             # Nested namespaces under the blink namespace
+            '[a-z_]+_names::.+',
             'bindings::.+',
             'canvas_heuristic_parameters::.+',
             'compositor_target_property::.+',
@@ -630,6 +632,7 @@ _CONFIG = [
             'event_handling_util::.+',
             'event_util::.+',
             'file_error::.+',
+            'file_system_access_error::.+',
             'geometry_util::.+',
             'inspector_\\w+_event::.+',
             'inspector_async_task::.+',
@@ -641,7 +644,6 @@ _CONFIG = [
             'layout_text_control::.+',
             'media_constraints_impl::.+',
             'media_element_parser_helpers::.+',
-            'file_system_access_error::.+',
             'network_utils::.+',
             'origin_trials::.+',
             'paint_filter_builder::.+',
@@ -656,22 +658,21 @@ _CONFIG = [
             'touch_action_util::.+',
             'trace_event::.+',
             'unicode::.+',
-            'vector_math::.+',
             'v8_compile_hints::.+',
+            'vector_math::.+',
             'web_core_test_support::.+',
             'worker_pool::.+',
             'xpath::.+',
-            '[a-z_]+_names::.+',
 
             # Third-party libraries that don't depend on non-Blink Chrome code
             # are OK.
             'icu::.+',
+            'inspector_protocol_encoding::.+',
             'perfetto::.+',  # tracing
+            'snappy::.+',
             'testing::.+',  # googlemock / googletest
             'v8::.+',
             'v8_inspector::.+',
-            'inspector_protocol_encoding::.+',
-            'snappy::.+',
 
             # Inspector instrumentation and protocol
             'probe::.+',
@@ -691,14 +692,14 @@ _CONFIG = [
             # CanonicalCookie and related headers
             'net::CanonicalCookie',
             'net::CookieInclusionStatus',
-            'net::CookiePriority',
             'net::CookiePartitionKey',
+            'net::CookiePriority',
             'net::CookieSameSite',
             'net::CookieSourceScheme',
 
             # HTTP status codes
-            'net::HTTP_.+',
             'net::ERR_.*',
+            'net::HTTP_.+',
 
             # For ConnectionInfo enumeration
             'net::HttpConnectionInfo',
@@ -728,9 +729,9 @@ _CONFIG = [
             # Note that the Mojo callback helpers are explicitly forbidden:
             # Blink already has a signal for contexts being destroyed, and
             # other types of failures should be explicitly signalled.
+            '(?:.+::)?mojom::.+',
             'mojo::(?!WrapCallback).+',
             'mojo_base::BigBuffer.*',
-            '(?:.+::)?mojom::.+',
             'service_manager::InterfaceProvider',
 
             # STL containers such as std::string and std::vector are discouraged
@@ -748,10 +749,10 @@ _CONFIG = [
             'ui::Cursor',
 
             # UI Pointer and Hover
-            'ui::PointerType',
-            'ui::POINTER_TYPE_.*',
-            'ui::HoverType',
             'ui::HOVER_TYPE_.*',
+            'ui::HoverType',
+            'ui::POINTER_TYPE_.*',
+            'ui::PointerType',
 
             # UI Keyconverter
             'ui::DomCode',
@@ -760,6 +761,10 @@ _CONFIG = [
 
             # Accessibility base types and the non-Blink enums they
             # depend on.
+            'ax::mojom::BoolAttribute',
+            'ax::mojom::HasPopup',
+            'ax::mojom::Restriction',
+            'ax::mojom::State',
             'ui::AXActionData',
             'ui::AXEvent',
             'ui::AXEventIntent',
@@ -768,21 +773,17 @@ _CONFIG = [
             'ui::AXRelativeBounds',
             'ui::AXTreeChecks',
             'ui::AXTreeData',
+            'ui::AXTreeID',
+            'ui::AXTreeIDUnknown',
             'ui::AXTreeSerializer',
             'ui::AXTreeSource',
             'ui::AXTreeUpdate',
-            'ui::AXTreeID',
-            'ui::AXTreeIDUnknown',
-            'ui::kInvalidAXNodeID',
-            'ui::kFirstGeneratedRendererNodeID',
-            'ui::kLastGeneratedRendererNodeID',
             'ui::kAXModeBasic',
             'ui::kAXModeComplete',
+            'ui::kFirstGeneratedRendererNodeID',
+            'ui::kInvalidAXNodeID',
+            'ui::kLastGeneratedRendererNodeID',
             'ui::ToString',
-            'ax::mojom::BoolAttribute',
-            'ax::mojom::HasPopup',
-            'ax::mojom::State',
-            'ax::mojom::Restriction',
 
             # Accessibility helper functions - mostly used in Blink for
             # serialization. Please keep alphabetized.
@@ -866,9 +867,9 @@ _CONFIG = [
         'allowed': [
             # For the script streaming to be able to block when reading from a
             # mojo datapipe.
+            'base::BlockingType',
             'base::ScopedAllowBaseSyncPrimitives',
             'base::ScopedBlockingCall',
-            'base::BlockingType',
         ],
     },
     {
@@ -946,18 +947,18 @@ _CONFIG = [
         'allowed': [
             'cc::ActiveFrameSequenceTrackers',
             'cc::ApplyViewportChangesArgs',
-            'cc::LayerTreeSettings',
-            'cc::PaintBenchmarkResult',
-            'cc::RenderFrameMetadata',
-            'cc::TaskGraphRunner',
             'cc::ContentLayerClient',
             'cc::DeadlinePolicy',
             'cc::DisplayItemList',
             'cc::DrawColorOp',
             'cc::DrawImageOp',
+            'cc::LayerTreeSettings',
+            'cc::PaintBenchmarkResult',
+            'cc::RenderFrameMetadata',
+            'cc::RestoreOp',
             'cc::SaveOp',
             'cc::ScaleOp',
-            'cc::RestoreOp',
+            'cc::TaskGraphRunner',
             'cc::TranslateOp',
             'gfx::DisplayColorSpaces',
             'gfx::FontRenderParams',
@@ -1371,17 +1372,17 @@ _CONFIG = [
         # display-related types.
         'allowed': [
             'base::flat_map',
+            'display::Display',
             'gl::GpuPreference',
             'gpu::ClientSharedImage',
-            'gpu::SHARED_IMAGE_USAGE_.+',
             'gpu::gles2::GLES2Interface',
-            'gpu::raster::RasterInterface',
             'gpu::Mailbox',
             'gpu::MailboxHolder',
+            'gpu::raster::RasterInterface',
+            'gpu::SHARED_IMAGE_USAGE_.+',
             'gpu::SharedImageInterface',
             'gpu::SyncToken',
             'gpu::webgpu::ReservedTexture',
-            'display::Display',
             'media::IsOpaque',
             'media::kNoTransformation',
             'media::PaintCanvasVideoRenderer',
@@ -1535,17 +1536,17 @@ _CONFIG = [
             'third_party/blink/renderer/modules/mediarecorder/',
         ],
         'allowed': [
-            # TODO(crbug.com/960665): Remove base::queue once it is replaced with a WTF equivalent.
-            'base::queue',
             'base::ClampMul',
             'base::MakeFixedFlatMap',
+            'base::NumberToString',
+            # TODO(crbug.com/960665): Remove base::queue once it is replaced with a WTF equivalent.
+            'base::queue',
             'base::SharedMemory',
             'base::StringPiece',
-            'base::NumberToString',
             'base::ThreadTaskRunnerHandle',
-            'media::.+',
             'libopus::.+',
             'libyuv::.+',
+            'media::.+',
             'video_track_recorder::.+',
         ],
         'inclass_allowed': [
@@ -1621,8 +1622,8 @@ _CONFIG = [
         ],
         'allowed': [
             'base::ClampMul',
-            'base::IsAligned',
             'base::DoNothingWithBoundArgs',
+            'base::IsAligned',
             'base::PlatformThreadRef',
             'base::WrapRefCounted',
             'cc::kNumYUVPlanes',
@@ -1630,17 +1631,17 @@ _CONFIG = [
             'cc::YUVIndex',
             'cc::YUVSubsampling',
             'gpu::kNullSurfaceHandle',
-            'gpu::SHARED_IMAGE_.+',
-            'gpu::raster::RasterInterface',
             'gpu::Mailbox',
             'gpu::MailboxHolder',
+            'gpu::raster::RasterInterface',
+            'gpu::SHARED_IMAGE_.+',
             'gpu::SharedImageInterface',
             'gpu::SyncToken',
-            'viz::RasterContextProvider',
-            'viz::ReleaseCallback',
-            'media::.+',
             'libgav1::.+',
             'libyuv::.+',
+            'media::.+',
+            'viz::RasterContextProvider',
+            'viz::ReleaseCallback',
         ]
     },
     {

ui/aura/demo/demo_main.cc

@@ -191,7 +191,7 @@ int DemoMain() {
   auto context_factory = std::make_unique<ui::InProcessContextFactory>(
       &host_frame_sink_manager, &frame_sink_manager, /*output_to_window=*/true);
 
-  base::PowerMonitor::Initialize(
+  base::PowerMonitor::GetInstance()->Initialize(
       std::make_unique<base::PowerMonitorDeviceSource>());
 
   std::unique_ptr<aura::Env> env = aura::Env::CreateInstance();

ui/compositor/compositor.cc

@@ -267,8 +267,10 @@ Compositor::Compositor(const viz::FrameSinkId& frame_sink_id,
   // See: http://crbug.com/956264.
   host_->SetVisible(true);
 
-  if (base::PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    base::PowerMonitor::AddPowerSuspendObserver(this);
+      power_monitor->IsInitialized()) {
+    power_monitor->AddPowerSuspendObserver(this);
+  }
 
   if (command_line->HasSwitch(switches::kUISlowAnimations)) {
     slow_animations_ = std::make_unique<ScopedAnimationDurationScaleMode>(
@@ -281,8 +283,10 @@ Compositor::Compositor(const viz::FrameSinkId& frame_sink_id,
 
 Compositor::~Compositor() {
   TRACE_EVENT0("shutdown,viz", "Compositor::destructor");
-  if (base::PowerMonitor::IsInitialized())
+  if (auto* power_monitor = base::PowerMonitor::GetInstance();
-    base::PowerMonitor::RemovePowerSuspendObserver(this);
+      power_monitor->IsInitialized()) {
+    power_monitor->RemovePowerSuspendObserver(this);
+  }
 
   for (auto& observer : observer_list_)
     observer.OnCompositingShuttingDown(this);

ui/gl/swap_chain_presenter.cc

@@ -504,11 +504,11 @@ SwapChainPresenter::SwapChainPresenter(
       d3d11_device_(d3d11_device),
       dcomp_device_(dcomp_device),
       is_on_battery_power_(
-          base::PowerMonitor::AddPowerStateObserverAndReturnOnBatteryState(
+          base::PowerMonitor::GetInstance()
-              this)) {}
+              ->AddPowerStateObserverAndReturnOnBatteryState(this)) {}
 
 SwapChainPresenter::~SwapChainPresenter() {
-  base::PowerMonitor::RemovePowerStateObserver(this);
+  base::PowerMonitor::GetInstance()->RemovePowerStateObserver(this);
 }
 
 DXGI_FORMAT SwapChainPresenter::GetSwapChainFormat(

ui/gl/vsync_thread_win.cc

@@ -177,8 +177,8 @@ VSyncThreadWin::VSyncThreadWin(Microsoft::WRL::ComPtr<IDXGIDevice> dxgi_device)
       vsync_provider_(gfx::kNullAcceleratedWidget),
       dxgi_adapter_(GetAdapter(dxgi_device.Get())),
       original_adapter_luid_(GetLuid(dxgi_adapter_.Get())) {
-  is_suspended_ =
+  is_suspended_ = base::PowerMonitor::GetInstance()
-      base::PowerMonitor::AddPowerSuspendObserverAndReturnSuspendedState(this);
+                      ->AddPowerSuspendObserverAndReturnSuspendedState(this);
   vsync_thread_.StartWithOptions(
       base::Thread::Options(base::ThreadType::kDisplayCritical));
 }