Implement base::PowerMonitor::IsOnBatteryPower() for OSX.

base/power_monitor/power_monitor_source.h

 // Copyright 2013 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_POWER_MONITOR_POWER_MONITOR_SOURCE_H_
 #define BASE_POWER_MONITOR_POWER_MONITOR_SOURCE_H_
 
 #include "base/base_export.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 31 matching lines @@
 
   // ProcessPowerEvent should only be called from a single thread, most likely
   // the UI thread or, in child processes, the IO thread.
   static void ProcessPowerEvent(PowerEvent event_id);
 
   // Platform-specific method to check whether the system is currently
   // running on battery power.  Returns true if running on batteries,
   // false otherwise.
   virtual bool IsOnBatteryPowerImpl() = 0;
 
+  // Sets the initial state for |on_battery_power_|, which defaults to false
+  // since not all implementations can provide the value at construction. May
+  // only be called before a base::PowerMonitor has been created.
+  void SetInitialOnBatteryPowerState(bool on_battery_power);
+
  private:
-  bool on_battery_power_;
-  bool suspended_;
+  bool on_battery_power_ = false;
+  bool suspended_ = false;
 
   // This lock guards access to on_battery_power_, to ensure that
   // IsOnBatteryPower can be called from any thread.
   Lock battery_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerMonitorSource);
 };
 
 }  // namespace base
 
 #endif  // BASE_POWER_MONITOR_POWER_MONITOR_SOURCE_H_