ash: Add one second grace period For LockScreenIfRequired

ash/system/chromeos/power/tablet_power_button_controller.h

 // Copyright 2016 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 ASH_SYSTEM_CHROMEOS_POWER_TABLET_POWER_BUTTON_CONTROLLER_H_
 #define ASH_SYSTEM_CHROMEOS_POWER_TABLET_POWER_BUTTON_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 24 matching lines @@
    public:
     explicit TestApi(TabletPowerButtonController* controller);
     ~TestApi();
 
     // Returns true when |shutdown_timer_| is running.
     bool ShutdownTimerIsRunning() const;
 
     // Emulates |shutdown_timer_| timeout.
     void TriggerShutdownTimeout();
 
+    // Returns true when |lock_screen_timer_| is running.
+    bool LockScreenTimerIsRunning() const;
+
+    // Emulates |lock_screen_timer_| timeout.
+    void TriggerLockScreenTimeout();
+
    private:
     TabletPowerButtonController* controller_;  // Not owned.
 
     DISALLOW_COPY_AND_ASSIGN(TestApi);
   };
 
   explicit TabletPowerButtonController(LockStateController* controller);
   ~TabletPowerButtonController() override;
 
   // Returns true if power button events should be handled by this class instead
@@ skipping 39 matching lines @@
   // tablet mode.
   void StartShutdownTimer();
 
   // Called by |shutdown_timer_| to start the pre-shutdown animation.
   void OnShutdownTimeout();
 
   // Locks the screen if the "require password to wake from sleep" pref is set
   // and locking is possible.
   void LockScreenIfRequired();
 
+  // Called by |lock_screen_timer_| to start locking screen.
+  void OnLockScreenTimeout();
+
   // True if the brightness level is currently set to off.
   bool brightness_level_is_zero_ = false;
 
   // Current forced-off state of backlights.
   bool backlights_forced_off_ = false;
 
   // True if the screen was off when the power button was pressed.
   bool screen_off_when_power_button_down_ = false;
 
   // Time source for performed action times.
   std::unique_ptr<base::TickClock> tick_clock_;
 
   // Saves the most recent timestamp that powerd is resuming from suspend,
   // updated in SuspendDone().
   base::TimeTicks last_resume_time_;
 
   // True if power button released should force off display.
   bool force_off_on_button_up_;
 
   // Started when the tablet power button is pressed and stopped when it's
   // released. Runs OnShutdownTimeout() to start shutdown.
   base::OneShotTimer shutdown_timer_;
 
+  // Started when |shutdown_timer_| is still running when tablet power button is
+  // released and it should SetDisplayForcedOff(true), and stopped when it times
+  // out. Resets timer whenever there is a call of SetDisplayForcedOff(false).

[Daniel Erat, 2017/01/12 01:40:47]

this is a pretty complicated comment. could you use something simpler like:

// Used to provide a grace period between forcing the display off and
// locking the screen. Runs OnLockScreenTimeout().

? someone can/should look at the code if they want to see the specific logic for
when it's started. :-)

[Qiang(Joe) Xu, 2017/01/12 15:05:55]

done, thanks

+  // Runs OnLockScreenTimeout() to start locking screen.
+  base::OneShotTimer lock_screen_timer_;
+
   LockStateController* controller_;  // Not owned.
 
   base::WeakPtrFactory<TabletPowerButtonController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabletPowerButtonController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_POWER_TABLET_POWER_BUTTON_CONTROLLER_H_