Ignore OnKeyEvent for VKEY_POWER because it is handled by PowerButtonEvent

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"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/lock_state_controller_test_api.h"
 #include "ash/wm/lock_state_controller.h"
 #include "ash/wm/power_button_controller.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/run_loop.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/fake_power_manager_client.h"
+#include "ui/events/event.h"
 #include "ui/events/test/event_generator.h"
 
 namespace ash {
 namespace test {
 
 namespace {
 
 // A non-zero brightness used for test.
 constexpr int kNonZeroBrightness = 10;
 
@@ skipping 258 matching lines @@
 
   generator_->MoveMouseBy(1, 1);
   EXPECT_TRUE(GetBacklightsForcedOff());
 
   generator_->EnterPenPointerMode();
   generator_->MoveMouseBy(1, 1);
   EXPECT_TRUE(GetBacklightsForcedOff());
   generator_->ExitPenPointerMode();
 }
 
+// Tests that a single set of power button pressed-and-released operation should
+// cause only one SetBacklightsForcedOff call.
+TEST_F(TabletPowerButtonControllerTest, IgnorePowerOnKeyEvent) {
+  ui::KeyEvent power_key_pressed(ui::ET_KEY_PRESSED, ui::VKEY_POWER,
+                                 ui::EF_NONE);
+  ui::KeyEvent power_key_released(ui::ET_KEY_RELEASED, ui::VKEY_POWER,
+                                  ui::EF_NONE);
+
+  int expectation =
+      power_manager_client_->num_set_backlights_forced_off_calls() + 1;

[Daniel Erat, 2016/11/22 00:48:19]

does this count really not start out at zero? it looks like you're creating a
new FakePowerManagerClient in SetUp (which is run for each test), so this is
surprising.

[Qiang(Joe) Xu, 2016/11/22 01:02:50]

It should start with zero. Thanks for pointing out.

+  // There can be multiple |power_key_pressed| and |power_key_released| events
+  // depends on the duration of holding.
+  tablet_controller_->OnKeyEvent(&power_key_pressed);
+  PressPowerButton();
+  tablet_controller_->OnKeyEvent(&power_key_pressed);
+  tablet_controller_->OnKeyEvent(&power_key_pressed);
+  tablet_controller_->OnKeyEvent(&power_key_released);

[Daniel Erat, 2016/11/22 00:48:19]

are there really multiple release events? i'd expect there to be multiple press
events (for autorepeat) but only one release event.

[Qiang(Joe) Xu, 2016/11/22 01:02:51]

Yes, there are multiple release events. I made the logs before I wrote the
tests. Please see https://paste.googleplex.com/6168565862367232.

+  ReleasePowerButton();
+  tablet_controller_->OnKeyEvent(&power_key_released);
+  EXPECT_EQ(power_manager_client_->num_set_backlights_forced_off_calls(),

[Daniel Erat, 2016/11/22 00:48:19]

nit: the order should be EXPECT_EQ(expected, actual) in order for the failure
messages to make sense

[Qiang(Joe) Xu, 2016/11/22 01:02:50]

Done.

+            expectation);
+}
+
 }  // namespace test
 }  // namespace ash