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

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index ac0b9472f1cb64d205c5fe6d371792f3503b58b4..8fd91d9338cc168bcc6ae5147f1f9d87a7d9f564 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -12,6 +12,7 @@
 #include "base/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
+#include "base/power_state_manager.h"
 #include "base/run_loop.h"
 #include "base/string_number_conversions.h"
 #include "base/threading/thread_restrictions.h"
@@ -333,6 +334,7 @@ void BrowserMainLoop::MainMessageLoopStart() {
   InitializeMainThread();
 
   system_monitor_.reset(new base::SystemMonitor);
+  power_state_manager_.reset(new base::PowerStateManager);
   hi_res_timer_manager_.reset(new HighResolutionTimerManager);
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
   audio_manager_.reset(media::AudioManager::Create());