Make SystemMonitor not a Singleton and move it out of base

SystemMonitor makes an assumption that through its lifetime a MessageLoop exists and stays the same. It is difficult and error-prone to satisfy that when it is a Singleton. It has caused problems in the past.

Additionally, extract HighResoltionTimerManager out of time_win.cc, eliminating yet another Singleton.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/431008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33214 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 0 insertions, 129 deletions

diff --git a/base/system_monitor.h b/base/system_monitor.h
deleted file mode 100644
index 71d8436..0000000
--- a/base/system_monitor.h
+++ /dev/null
@@ -1,129 +0,0 @@
-// Copyright (c) 2009 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 BASE_SYSTEM_MONITOR_H_
-#define BASE_SYSTEM_MONITOR_H_
-
-#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)
-
-namespace base {
-
-// 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:
-  // Retrieves the Singleton.
-  static SystemMonitor* Get();
-
-  // Start the System Monitor within a process.  This method
-  // is provided so that the battery check can be deferred.
-  // The MessageLoop must be started before calling this
-  // method.
-  // This is a no-op on platforms for which ENABLE_BATTERY_MONITORING is
-  // disabled.
-  static void Start();
-
-  //
-  // 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_;
-  }
-
-  // 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.
-  };
-
-  // 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() {}
-  };
-
-  // 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);
-
-  // Constructor.
-  // Don't use this; access SystemMonitor via the Singleton.
-  SystemMonitor();
-
- private:
-  // 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
-
-  DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
-};
-
-}
-
-#endif  // BASE_SYSTEM_MONITOR_H_