Move SystemMonitor to src/chrome/common....

app/system_monitor.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef APP_SYSTEM_MONITOR_H_
-#define APP_SYSTEM_MONITOR_H_
-#pragma once
-
-#include "build/build_config.h"
-
-// Windows HiRes timers drain the battery faster so we need to know the battery
-// status.  This isn't true for other platforms.
-#if defined(OS_WIN)
-#define ENABLE_BATTERY_MONITORING 1
-#else
-#undef ENABLE_BATTERY_MONITORING
-#endif  // !OS_WIN
-
-#include "base/observer_list_threadsafe.h"
-#if defined(ENABLE_BATTERY_MONITORING)
-#include "base/timer.h"
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-
-#if defined(OS_MACOSX)
-#ifdef __OBJC__
-@class SystemMonitorBridge;
-#else
-class SystemMonitorBridge;
-#endif
-#endif
-
-// Class for monitoring various system-related subsystems
-// such as power management, network status, etc.
-// TODO(mbelshe):  Add support beyond just power management.
-class SystemMonitor {
- public:
-  // Normalized list of power events.
-  enum PowerEvent {
-    POWER_STATE_EVENT,  // The Power status of the system has changed.
-    SUSPEND_EVENT,      // The system is being suspended.
-    RESUME_EVENT        // The system is being resumed.
-  };
-
-  // Create SystemMonitor. Only one SystemMonitor instance per application
-  // is allowed.
-  SystemMonitor();
-  ~SystemMonitor();
-
-  // Get the application-wide SystemMonitor (if not present, returns NULL).
-  static SystemMonitor* Get();
-
-  //
-  // Power-related APIs
-  //
-
-  // Is the computer currently on battery power.
-  // Can be called on any thread.
-  bool BatteryPower() const {
-    // Using a lock here is not necessary for just a bool.
-    return battery_in_use_;
-  }
-
-  // Callbacks will be called on the thread which creates the SystemMonitor.
-  // During the callback, Add/RemoveObserver will block until the callbacks
-  // are finished. Observers should implement quick callback functions; if
-  // lengthy operations are needed, the observer should take care to invoke
-  // the operation on an appropriate thread.
-  class PowerObserver {
-   public:
-    // Notification of a change in power status of the computer, such
-    // as from switching between battery and A/C power.
-    virtual void OnPowerStateChange(bool on_battery_power) {}
-
-    // Notification that the system is suspending.
-    virtual void OnSuspend() {}
-
-    // Notification that the system is resuming.
-    virtual void OnResume() {}
-
-   protected:
-    virtual ~PowerObserver() {}
-  };
-
-  // Add a new observer.
-  // Can be called from any thread.
-  // Must not be called from within a notification callback.
-  void AddObserver(PowerObserver* obs);
-
-  // Remove an existing observer.
-  // Can be called from any thread.
-  // Must not be called from within a notification callback.
-  void RemoveObserver(PowerObserver* obs);
-
-#if defined(OS_WIN)
-  // Windows-specific handling of a WM_POWERBROADCAST message.
-  // Embedders of this API should hook their top-level window
-  // message loop and forward WM_POWERBROADCAST through this call.
-  void ProcessWmPowerBroadcastMessage(int event_id);
-#endif
-
-  // Cross-platform handling of a power event.
-  void ProcessPowerMessage(PowerEvent event_id);
-
- private:
-#if defined(OS_MACOSX)
-  void PlatformInit();
-  void PlatformDestroy();
-#endif
-
-  // Platform-specific method to check whether the system is currently
-  // running on battery power.  Returns true if running on batteries,
-  // false otherwise.
-  bool IsBatteryPower();
-
-  // Checks the battery status and notifies observers if the battery
-  // status has changed.
-  void BatteryCheck();
-
-  // Functions to trigger notifications.
-  void NotifyPowerStateChange();
-  void NotifySuspend();
-  void NotifyResume();
-
-  scoped_refptr<ObserverListThreadSafe<PowerObserver> > observer_list_;
-  bool battery_in_use_;
-  bool suspended_;
-
-#if defined(ENABLE_BATTERY_MONITORING)
-  base::OneShotTimer<SystemMonitor> delayed_battery_check_;
-#endif
-
-#if defined(OS_MACOSX)
-  SystemMonitorBridge* system_monitor_bridge_;
-#endif
-
-  DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
-};
-
-#endif  // APP_SYSTEM_MONITOR_H_