[sensors] PlatformSensorProvider implementations are notified when there are no sensor instances

device/generic_sensor/platform_sensor_provider_unittest.cc

Index: device/generic_sensor/platform_sensor_provider_unittest.cc
diff --git a/device/generic_sensor/platform_sensor_provider_unittest.cc b/device/generic_sensor/platform_sensor_provider_unittest.cc
index bccdad7fb033a5bb84447b3f943bba725cda83c1..35e5019977f48ce012137b7ae5fedb2d6f6a5b9e 100644
--- a/device/generic_sensor/platform_sensor_provider_unittest.cc
+++ b/device/generic_sensor/platform_sensor_provider_unittest.cc
@@ -87,19 +87,19 @@ class PlatformSensorTestClient : public PlatformSensor::Client {
 class PlatformSensorProviderTest : public ::testing::Test {
  public:
   PlatformSensorProviderTest()
-      : sensor_client_(new PlatformSensorTestClient()) {
-    message_loop_.reset(new base::MessageLoopForIO);
-  }
+      : provider_(new FakePlatformSensorProvider()),
+        sensor_client_(new PlatformSensorTestClient()),
+        message_loop_(new base::MessageLoopForIO) {}
 
  protected:
   scoped_refptr<PlatformSensor> CreateSensor(
       mojom::SensorType type,
       TestSensorCreateCallback* callback) {
-    FakePlatformSensorProvider::GetInstance()->CreateSensor(
-        type, callback->callback());
+    provider_->CreateSensor(type, callback->callback());
     return callback->WaitForResult();
   }
 
+  std::unique_ptr<FakePlatformSensorProvider> provider_;
   std::unique_ptr<PlatformSensorTestClient> sensor_client_;
   std::unique_ptr<base::MessageLoop> message_loop_;
 };
@@ -137,9 +137,6 @@ TEST_F(PlatformSensorProviderTest, CreateSensorsAndCheckType) {
 }
 
 TEST_F(PlatformSensorProviderTest, CreateAndGetSensor) {
-  PlatformSensorProvider* sensor_provider =
-      FakePlatformSensorProvider::GetInstance();
-
   // Create Ambient Light sensor.
   TestSensorCreateCallback callback1;
   scoped_refptr<PlatformSensor> sensor1 =
@@ -149,21 +146,39 @@ TEST_F(PlatformSensorProviderTest, CreateAndGetSensor) {
 
   // Try to get Gyroscope sensor, which has not been created yet.
   scoped_refptr<PlatformSensor> sensor2 =
-      sensor_provider->GetSensor(SensorType::GYROSCOPE);
+      provider_->GetSensor(SensorType::GYROSCOPE);
   EXPECT_FALSE(sensor2);
 
   // Get Ambient Light sensor.
   scoped_refptr<PlatformSensor> sensor3 =
-      sensor_provider->GetSensor(SensorType::AMBIENT_LIGHT);
+      provider_->GetSensor(SensorType::AMBIENT_LIGHT);
   EXPECT_TRUE(sensor3);
 
   EXPECT_EQ(sensor1->GetType(), sensor3->GetType());
 }
 
-TEST_F(PlatformSensorProviderTest, TestSensorLeaks) {
-  PlatformSensorProvider* sensor_provider =
-      FakePlatformSensorProvider::GetInstance();
+TEST_F(PlatformSensorProviderTest, CreateAndRemoveSensors) {
+  TestSensorCreateCallback callback1;
+  scoped_refptr<PlatformSensor> sensor1 =
+      CreateSensor(SensorType::AMBIENT_LIGHT, &callback1);
+  EXPECT_TRUE(sensor1);
 
+  TestSensorCreateCallback callback2;
+  scoped_refptr<PlatformSensor> sensor2 =
+      CreateSensor(SensorType::PROXIMITY, &callback2);
+  EXPECT_TRUE(sensor2);
+
+  EXPECT_TRUE(provider_->HasSensors());
+
+  EXPECT_CALL(*provider_, AllSensorsRemoved()).Times(1);
+
+  sensor1 = nullptr;
+  sensor2 = nullptr;
+
+  EXPECT_FALSE(provider_->HasSensors());
+}
+
+TEST_F(PlatformSensorProviderTest, TestSensorLeaks) {
   // Create Ambient Light sensor.
   TestSensorCreateCallback callback1;
   scoped_refptr<PlatformSensor> sensor1 =
@@ -174,7 +189,7 @@ TEST_F(PlatformSensorProviderTest, TestSensorLeaks) {
   // Sensor should be automatically destroyed.
   sensor1 = nullptr;
   scoped_refptr<PlatformSensor> sensor2 =
-      sensor_provider->GetSensor(SensorType::AMBIENT_LIGHT);
+      provider_->GetSensor(SensorType::AMBIENT_LIGHT);
   EXPECT_FALSE(sensor2);
 }