ash: Drop the immediately following power button released induced forcing off request

ash/system/chromeos/power/tablet_power_button_controller_unittest.cc

 // 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.
 
 #include "ash/system/chromeos/power/tablet_power_button_controller.h"
 
 #include <memory>
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/session/session_state_delegate.h"
@@ skipping 421 matching lines @@
   test_api_->TriggerShutdownTimeout();
   EXPECT_TRUE(lock_state_test_api_->shutdown_timer_is_running());
   tablet_controller_->OnMaximizeModeEnded();
   EXPECT_FALSE(lock_state_test_api_->shutdown_timer_is_running());
   tick_clock_->Advance(base::TimeDelta::FromMilliseconds(4500));
   power_manager_client_->SendPowerButtonEvent(false, tick_clock_->NowTicks());
   EXPECT_FALSE(GetLockedState());
   EXPECT_FALSE(GetBacklightsForcedOff());
 }
 
+// Tests that repeated power button releases are ignored (crbug.com/675291).
+TEST_F(TabletPowerButtonControllerTest, IgnoreRepeatedPowerButtonReleases) {
+  // Advance a long duration from initialized last resume time in
+  // |tablet_controller_| to avoid cross interference.
+  tick_clock_->Advance(base::TimeDelta::FromMilliseconds(2000));
+
+  // Set backlights forced off for starting point.
+  PressPowerButton();
+  ReleasePowerButton();
+  power_manager_client_->SendBrightnessChanged(0, false);
+  EXPECT_TRUE(GetBacklightsForcedOff());
+
+  // Test that a pressing-releasing operation after a short duration, backlights
+  // forced off is stopped since we don't drop request for power button pressed.
+  tick_clock_->Advance(base::TimeDelta::FromMilliseconds(200));
+  power_manager_client_->SendPowerButtonEvent(true, tick_clock_->NowTicks());
+  power_manager_client_->SendBrightnessChanged(kNonZeroBrightness, false);
+  power_manager_client_->SendPowerButtonEvent(false, tick_clock_->NowTicks());
+  EXPECT_FALSE(GetBacklightsForcedOff());
+
+  // Test that after another short duration, backlights will not be forced off
+  // since this immediately following forcing off request needs to be dropped.
+  tick_clock_->Advance(base::TimeDelta::FromMilliseconds(200));
+  power_manager_client_->SendPowerButtonEvent(true, tick_clock_->NowTicks());
+  power_manager_client_->SendPowerButtonEvent(false, tick_clock_->NowTicks());
+  EXPECT_FALSE(GetBacklightsForcedOff());
+
+  // Test that after another long duration, backlights should be forced off.
+  tick_clock_->Advance(base::TimeDelta::FromMilliseconds(800));
+  power_manager_client_->SendPowerButtonEvent(true, tick_clock_->NowTicks());
+  power_manager_client_->SendPowerButtonEvent(false, tick_clock_->NowTicks());
+  power_manager_client_->SendBrightnessChanged(0, false);
+  EXPECT_TRUE(GetBacklightsForcedOff());
+}
+
 }  // namespace test
 }  // namespace ash