ash: Add one second grace period For LockScreenIfRequired

Changes:
Add one second grace period For LockScreenIfRequired. Basically, an one second OneShotTimer is used to set/reset the behavior.

BUG=633304
BUG=680509
TEST=device test, and modify test coverage

Review-Url: https://codereview.chromium.org/2620383003
Cr-Commit-Position: refs/heads/master@{#443254}

ash/system/chromeos/power/tablet_power_button_controller.cc

@@ -25,6 +25,9 @@ namespace {
 // animation when in tablet mode.
 constexpr int kShutdownTimeoutMs = 500;
 
+// Amount of time to delay locking screen after display is forced off.
+constexpr int kLockScreenTimeoutMs = 1000;
+
 // Amount of time since last SuspendDone() that power button event needs to be
 // ignored.
 constexpr int kIgnorePowerButtonAfterResumeMs = 2000;
@@ -64,6 +67,16 @@ void TabletPowerButtonController::TestApi::TriggerShutdownTimeout() {
   controller_->shutdown_timer_.Stop();
 }
 
+bool TabletPowerButtonController::TestApi::LockScreenTimerIsRunning() const {
+  return controller_->lock_screen_timer_.IsRunning();
+}
+
+void TabletPowerButtonController::TestApi::TriggerLockScreenTimeout() {
+  DCHECK(LockScreenTimerIsRunning());
+  controller_->OnLockScreenTimeout();
+  controller_->lock_screen_timer_.Stop();
+}
+
 TabletPowerButtonController::TabletPowerButtonController(
     LockStateController* controller)
     : tick_clock_(new base::DefaultTickClock()),
@@ -108,6 +121,7 @@ void TabletPowerButtonController::OnPowerButtonEvent(
     }
     screen_off_when_power_button_down_ = brightness_level_is_zero_;
     SetDisplayForcedOff(false);
+    lock_screen_timer_.Stop();
     StartShutdownTimer();
   } else {
     if (shutdown_timer_.IsRunning()) {
@@ -159,22 +173,27 @@ void TabletPowerButtonController::OnKeyEvent(ui::KeyEvent* event) {
   if (event->key_code() == ui::VKEY_POWER)
     return;
 
-  if (!IsTabletModeActive() && backlights_forced_off_)
+  if (!IsTabletModeActive() && backlights_forced_off_) {
     SetDisplayForcedOff(false);
+    lock_screen_timer_.Stop();
+  }
 }
 
 void TabletPowerButtonController::OnMouseEvent(ui::MouseEvent* event) {
   if (event->flags() & ui::EF_IS_SYNTHESIZED)
     return;
 
-  if (!IsTabletModeActive() && backlights_forced_off_)
+  if (!IsTabletModeActive() && backlights_forced_off_) {
     SetDisplayForcedOff(false);
+    lock_screen_timer_.Stop();
+  }
 }
 
 void TabletPowerButtonController::OnStylusStateChanged(ui::StylusState state) {
   if (IsTabletModeSupported() && state == ui::StylusState::REMOVED &&
       backlights_forced_off_) {
     SetDisplayForcedOff(false);
+    lock_screen_timer_.Stop();
   }
 }
 
@@ -234,8 +253,14 @@ void TabletPowerButtonController::LockScreenIfRequired() {
       session_state_delegate->CanLockScreen() &&
       !session_state_delegate->IsUserSessionBlocked() &&
       !controller_->LockRequested()) {
-    session_state_delegate->LockScreen();
+    lock_screen_timer_.Start(
+        FROM_HERE, base::TimeDelta::FromMilliseconds(kLockScreenTimeoutMs),
+        this, &TabletPowerButtonController::OnLockScreenTimeout);
   }
 }
 
+void TabletPowerButtonController::OnLockScreenTimeout() {
+  WmShell::Get()->GetSessionStateDelegate()->LockScreen();
+}
+
 }  // namespace ash

ash/system/chromeos/power/tablet_power_button_controller.h

@@ -42,6 +42,12 @@ class ASH_EXPORT TabletPowerButtonController
     // 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.
 
@@ -101,6 +107,9 @@ class ASH_EXPORT TabletPowerButtonController
   // 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;
 
@@ -124,6 +133,10 @@ class ASH_EXPORT TabletPowerButtonController
   // released. Runs OnShutdownTimeout() to start shutdown.
   base::OneShotTimer shutdown_timer_;
 
+  // Used to provide a grace period between forcing the display off and locking
+  // the screen. Runs OnLockScreenTimeout().
+  base::OneShotTimer lock_screen_timer_;
+
   LockStateController* controller_;  // Not owned.
 
   base::WeakPtrFactory<TabletPowerButtonController> weak_ptr_factory_;

ash/system/chromeos/power/tablet_power_button_controller_unittest.cc

@@ -139,11 +139,15 @@ TEST_F(TabletPowerButtonControllerTest, LockScreenIfRequired) {
   // automatic screen-locking was requested.
   PressPowerButton();
   ReleasePowerButton();
+  EXPECT_TRUE(test_api_->LockScreenTimerIsRunning());
+  EXPECT_FALSE(GetLockedState());
+  test_api_->TriggerLockScreenTimeout();
   EXPECT_TRUE(GetLockedState());
 
   // On locked state, power-button-press-release should do nothing.
   PressPowerButton();
   ReleasePowerButton();
+  EXPECT_FALSE(test_api_->LockScreenTimerIsRunning());
   EXPECT_TRUE(GetLockedState());
 
   // Unlock the sceen.
@@ -155,6 +159,26 @@ TEST_F(TabletPowerButtonControllerTest, LockScreenIfRequired) {
   SetShouldLockScreenAutomatically(false);
   PressPowerButton();
   ReleasePowerButton();
+  EXPECT_FALSE(test_api_->LockScreenTimerIsRunning());
+  EXPECT_FALSE(GetLockedState());
+}
+
+// Tests when display is on, quickly tapping power button two times, screen is
+// not locked.
+TEST_F(TabletPowerButtonControllerTest, LockScreenGracePeriodTest) {
+  Initialize(LoginStatus::USER);
+  SetShouldLockScreenAutomatically(true);
+  EXPECT_FALSE(GetLockedState());
+
+  PressPowerButton();
+  ReleasePowerButton();
+  power_manager_client_->SendBrightnessChanged(0, false);
+  EXPECT_TRUE(test_api_->LockScreenTimerIsRunning());
+  PressPowerButton();
+  power_manager_client_->SendBrightnessChanged(kNonZeroBrightness, false);
+  EXPECT_FALSE(test_api_->LockScreenTimerIsRunning());
+  ReleasePowerButton();
+  EXPECT_FALSE(test_api_->LockScreenTimerIsRunning());
   EXPECT_FALSE(GetLockedState());
 }