Add policies to control power management on the Chrome OS login screen

chrome/browser/chromeos/chrome_browser_main_chromeos.h

Index: chrome/browser/chromeos/chrome_browser_main_chromeos.h
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.h b/chrome/browser/chromeos/chrome_browser_main_chromeos.h
index 021313237bf444e379031a0c6251d1caba1ea923..ccee35904e385d2f0c80f53b080f4a7db90cdd07 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.h
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.h
@@ -26,6 +26,7 @@ class IdleActionWarningObserver;
 class MagnificationManager;
 class PeripheralBatteryObserver;
 class PowerButtonObserver;
+class PowerPrefs;
 class ResumeObserver;
 class ScreenLockObserver;
 class ScreensaverController;
@@ -80,6 +81,7 @@ class ChromeBrowserMainPartsChromeos : public ChromeBrowserMainPartsLinux {
   scoped_ptr<ScreenLockObserver> screen_lock_observer_;
   scoped_ptr<ScreensaverController> screensaver_controller_;
   scoped_ptr<PeripheralBatteryObserver> peripheral_battery_observer_;
+  scoped_ptr<PowerPrefs> power_prefs_;
   scoped_ptr<PowerButtonObserver> power_button_observer_;
   scoped_ptr<content::PowerSaveBlocker> retail_mode_power_save_blocker_;
   scoped_ptr<UserActivityNotifier> user_activity_notifier_;