Adds an iOS implementation of base::SystemMonitor.

base/system_monitor/system_monitor.h

 // 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.
 
 #ifndef BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/tuple.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)
 
-#if defined(OS_MACOSX)
+#if defined(OS_MACOSX) && !defined(OS_IOS)
 #include <IOKit/pwr_mgt/IOPMLib.h>
 #include <IOKit/IOMessage.h>
-#endif  // OS_MACOSX
+#endif  // OS_MACOSX && !OS_IOS
+
+#if defined(OS_IOS)
+#include <objc/runtime.h>  // For id.
+#endif  // OS_IOS
 
 class FilePath;
 
 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 BASE_EXPORT SystemMonitor {
  public:
@@ skipping 138 matching lines @@
   scoped_refptr<ObserverListThreadSafe<PowerObserver> > power_observer_list_;
   scoped_refptr<ObserverListThreadSafe<DevicesChangedObserver> >
       devices_changed_observer_list_;
   bool battery_in_use_;
   bool suspended_;
 
 #if defined(ENABLE_BATTERY_MONITORING)
   base::OneShotTimer<SystemMonitor> delayed_battery_check_;
 #endif
 
+#if defined(OS_IOS)
+  // Holds pointers to system event notification observers.
+  std::vector<id> notification_observers_;
+#endif
+
   MediaDeviceMap media_device_map_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
 };
 
 }  // namespace base
 
 #endif  // BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_