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

ash/system/power/tablet_power_button_controller_unittest.cc

Index: ash/system/power/tablet_power_button_controller_unittest.cc
diff --git a/ash/system/power/tablet_power_button_controller_unittest.cc b/ash/system/power/tablet_power_button_controller_unittest.cc
index a0bfcda0ff2b6cee8db96218a0b492809c22505a..3a5139d8205d784a9c97c758d2bb2f46d56294f3 100644
--- a/ash/system/power/tablet_power_button_controller_unittest.cc
+++ b/ash/system/power/tablet_power_button_controller_unittest.cc
@@ -558,5 +558,15 @@ TEST_F(TabletPowerButtonControllerTest, EnableOnAccelerometerUpdate) {
   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