Enabled/disable touch screen in TabletPowerButtonController

ash/system/chromeos/power/tablet_power_button_controller.h

Index: ash/system/chromeos/power/tablet_power_button_controller.h
diff --git a/ash/system/chromeos/power/tablet_power_button_controller.h b/ash/system/chromeos/power/tablet_power_button_controller.h
index 66a5b61de06058e5b0529b0648b2e59d9cf1563d..363521e57c8ca8513c0ec00ee37aac078254d8c3 100644
--- a/ash/system/chromeos/power/tablet_power_button_controller.h
+++ b/ash/system/chromeos/power/tablet_power_button_controller.h
@@ -72,8 +72,9 @@ class ASH_EXPORT TabletPowerButtonController
   void SetTickClockForTesting(std::unique_ptr<base::TickClock> tick_clock);
 
  private:
-  // Set backlights to |forced_off| if they aren't already.
-  void SetBacklightsForcedOff(bool forced_off);
+  // Set backlights to |forced_off| and the corresponding enabled state of

[Daniel Erat, 2016/12/02 21:48:56]

nit: maybe this?

// Updates the power manager's backlights-forced-off state and
// enables or disables the touchscreen. No-op if 
// |backlights_forced_off_| already equals |forced_off|.

[Qiang(Joe) Xu, 2016/12/02 23:55:10]

Done.

+  // touchscreen if they aren't already.
+  void SetDisplayForcedOff(bool forced_off);
 
   // Sends a request to powerd to get the backlights forced off state so that
   // |backlights_forced_off_| can be initialized.