cros: Suspend media sessions with display off trigger by tablet power button

ash/system/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/power/tablet_power_button_controller.h"
 
 #include <memory>
 
 #include "ash/ash_switches.h"
 #include "ash/public/cpp/config.h"
@@ skipping 540 matching lines @@
                            ->tablet_power_button_controller_for_test();
   EXPECT_FALSE(tablet_controller_);
 
   SendAccelerometerUpdate();
   tablet_controller_ = Shell::Get()
                            ->power_button_controller()
                            ->tablet_power_button_controller_for_test();
   EXPECT_TRUE(tablet_controller_);
 }
 
+// Tests that when backlights get forced off due to tablet power button, media
+// sessions should be suspended.
+TEST_F(TabletPowerButtonControllerTest, SuspendMediaSessions) {
+  ASSERT_FALSE(shell_delegate_->media_sessions_suspended());
+  PressPowerButton();
+  ReleasePowerButton();
+  ASSERT_TRUE(GetBacklightsForcedOff());
+  EXPECT_TRUE(shell_delegate_->media_sessions_suspended());
+}
+
 }  // namespace test
 }  // namespace ash