SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/system_monitor/system_monitor.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/system_monitor/system_monitor.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/time.h"
 
 namespace base {
 
 static SystemMonitor* g_system_monitor = NULL;
 
-#if defined(ENABLE_BATTERY_MONITORING)
-// The amount of time (in ms) to wait before running the initial
-// battery check.
-static int kDelayedBatteryCheckMs = 10 * 1000;
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-
 SystemMonitor::SystemMonitor()
-    : power_observer_list_(new ObserverListThreadSafe<PowerObserver>()),
-      devices_changed_observer_list_(
-          new ObserverListThreadSafe<DevicesChangedObserver>()),
-      battery_in_use_(false),
-      suspended_(false) {
+    :  devices_changed_observer_list_(
+          new ObserverListThreadSafe<DevicesChangedObserver>()) {
   DCHECK(!g_system_monitor);
   g_system_monitor = this;
-
-  DCHECK(MessageLoop::current());
-#if defined(ENABLE_BATTERY_MONITORING)
-  delayed_battery_check_.Start(FROM_HERE,
-      base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
-      &SystemMonitor::BatteryCheck);
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-#if defined(OS_MACOSX)
-  PlatformInit();
-#endif
 }
 
 SystemMonitor::~SystemMonitor() {
-#if defined(OS_MACOSX)
-  PlatformDestroy();
-#endif
   DCHECK_EQ(this, g_system_monitor);
   g_system_monitor = NULL;
 }
 
 // static
 SystemMonitor* SystemMonitor::Get() {
   return g_system_monitor;
 }
 
-void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
-  // Suppress duplicate notifications.  Some platforms may
-  // send multiple notifications of the same event.
-  switch (event_id) {
-    case POWER_STATE_EVENT:
-      {
-        bool on_battery = IsBatteryPower();
-        if (on_battery != battery_in_use_) {
-          battery_in_use_ = on_battery;
-          NotifyPowerStateChange();
-        }
-      }
-      break;
-    case RESUME_EVENT:
-      if (suspended_) {
-        suspended_ = false;
-        NotifyResume();
-      }
-      break;
-    case SUSPEND_EVENT:
-      if (!suspended_) {
-        suspended_ = true;
-        NotifySuspend();
-      }
-      break;
-  }
-}
-
 void SystemMonitor::ProcessDevicesChanged(DeviceType device_type) {
   NotifyDevicesChanged(device_type);
 }
 
-void SystemMonitor::AddPowerObserver(PowerObserver* obs) {
-  power_observer_list_->AddObserver(obs);
-}
-
-void SystemMonitor::RemovePowerObserver(PowerObserver* obs) {
-  power_observer_list_->RemoveObserver(obs);
-}
-
 void SystemMonitor::AddDevicesChangedObserver(DevicesChangedObserver* obs) {
   devices_changed_observer_list_->AddObserver(obs);
 }
 
 void SystemMonitor::RemoveDevicesChangedObserver(DevicesChangedObserver* obs) {
   devices_changed_observer_list_->RemoveObserver(obs);
 }
 
 void SystemMonitor::NotifyDevicesChanged(DeviceType device_type) {
   DVLOG(1) << "DevicesChanged with device type " << device_type;
   devices_changed_observer_list_->Notify(
       &DevicesChangedObserver::OnDevicesChanged, device_type);
 }
 
-void SystemMonitor::NotifyPowerStateChange() {
-  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
-           << " battery";
-  power_observer_list_->Notify(&PowerObserver::OnPowerStateChange,
-                               BatteryPower());
-}
-
-void SystemMonitor::NotifySuspend() {
-  DVLOG(1) << "Power Suspending";
-  power_observer_list_->Notify(&PowerObserver::OnSuspend);
-}
-
-void SystemMonitor::NotifyResume() {
-  DVLOG(1) << "Power Resuming";
-  power_observer_list_->Notify(&PowerObserver::OnResume);
-}
-
-void SystemMonitor::BatteryCheck() {
-  ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
-}
-
 }  // namespace base