ambient: Fix screen goes off when battery is full.

Bug: b/160202872
Test: unittest.
Change-Id: I355c704fd2adda7d96dfbb3c972964e2da7a1e6a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2275342
Commit-Queue: Meilin Wang <meilinw@chromium.org>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784515}

ash/ambient/ambient_controller.cc

@@ -80,6 +80,13 @@ std::string GetWidgetName() {
   return "InSessionAmbientModeContainer";
 }
 
+// Returns true if the device is currently connected to a charger.
+bool IsChargerConnected() {
+  return (PowerStatus::Get()->IsBatteryCharging() ||
+          PowerStatus::Get()->IsBatteryFull()) &&
+         PowerStatus::Get()->IsLinePowerConnected();
+}
+
 }  // namespace
 
 // AmbientController::InactivityMonitor----------------------------------
@@ -168,9 +175,8 @@ void AmbientController::OnAmbientUiVisibilityChanged(
       // This will be no-op if the view is already visible.
       container_view_->SetVisible(true);
 
-      if (PowerStatus::Get()->IsBatteryCharging()) {
-        // Requires wake lock to prevent display from sleeping when the battery
-        // is charging.
+      if (IsChargerConnected()) {
+        // Requires wake lock to prevent display from sleeping.
         AcquireWakeLock();
       }
       // Observes the |PowerStatus| on the battery charging status change for
@@ -262,7 +268,7 @@ void AmbientController::OnPowerStatusChanged() {
     return;
   }
 
-  if (PowerStatus::Get()->IsBatteryCharging()) {
+  if (IsChargerConnected()) {
     AcquireWakeLock();
   } else {
     ReleaseWakeLock();

ash/ambient/ambient_controller_unittest.cc

@@ -180,7 +180,7 @@ TEST_F(AmbientControllerTest,
 }
 
 TEST_F(AmbientControllerTest,
-       CheckAcquireAndReleaseWakeLockWhenBatteryChargingStateChanged) {
+       CheckAcquireAndReleaseWakeLockWhenBatteryStateChanged) {
   // Flush the loop first to ensure the |PowerStatus| has picked up the initial
   // status.
   base::RunLoop().RunUntilIdle();
@@ -189,6 +189,8 @@ TEST_F(AmbientControllerTest,
   power_manager::PowerSupplyProperties proto;
   proto.set_battery_state(
       power_manager::PowerSupplyProperties_BatteryState_DISCHARGING);
+  proto.set_external_power(
+      power_manager::PowerSupplyProperties_ExternalPower_DISCONNECTED);
   PowerStatus::Get()->SetProtoForTesting(proto);
   // Lock screen to start ambient mode.
   LockScreen();
@@ -200,6 +202,8 @@ TEST_F(AmbientControllerTest,
   // Connect the device with a charger.
   proto.set_battery_state(
       power_manager::PowerSupplyProperties_BatteryState_CHARGING);
+  proto.set_external_power(
+      power_manager::PowerSupplyProperties_ExternalPower_AC);
   PowerStatus::Get()->SetProtoForTesting(proto);
   // Notify the controller about the power status change, and flush the loop to
   // ensure the wake lock request has reached the wake lock provider.
@@ -210,9 +214,23 @@ TEST_F(AmbientControllerTest,
   EXPECT_EQ(1, GetNumOfActiveWakeLocks(
                    device::mojom::WakeLockType::kPreventDisplaySleep));
 
+  // Simulates a full battery.
+  proto.set_battery_state(
+      power_manager::PowerSupplyProperties_BatteryState_FULL);
+  proto.set_external_power(
+      power_manager::PowerSupplyProperties_ExternalPower_AC);
+  PowerStatus::Get()->SetProtoForTesting(proto);
+  ambient_controller()->OnPowerStatusChanged();
+
+  // Should keep the wake lock as the charger is still connected.
+  EXPECT_EQ(1, GetNumOfActiveWakeLocks(
+                   device::mojom::WakeLockType::kPreventDisplaySleep));
+
   // Disconnects the charger again.
   proto.set_battery_state(
       power_manager::PowerSupplyProperties_BatteryState_DISCHARGING);
+  proto.set_external_power(
+      power_manager::PowerSupplyProperties_ExternalPower_DISCONNECTED);
   PowerStatus::Get()->SetProtoForTesting(proto);
   ambient_controller()->OnPowerStatusChanged();
   base::RunLoop().RunUntilIdle();