[sensors] [mac] Implement ambient light sensor for macOS

device/generic_sensor/platform_sensor_ambient_light_mac.h

Index: device/generic_sensor/platform_sensor_ambient_light_mac.h
diff --git a/device/generic_sensor/platform_sensor_ambient_light_mac.h b/device/generic_sensor/platform_sensor_ambient_light_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..44a0481f1d3ad239ad2eb462f5bb9a431aa515b5
--- /dev/null
+++ b/device/generic_sensor/platform_sensor_ambient_light_mac.h
@@ -0,0 +1,41 @@
+// 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.
+
+#ifndef DEVICE_GENERIC_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_MAC_H_
+#define DEVICE_GENERIC_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_MAC_H_
+
+#include "base/memory/ref_counted.h"
+#include "device/generic_sensor/platform_sensor_mac.h"
+
+namespace device {
+
+class AmbientLightSensor;
+
+class PlatformSensorAmbientLightMac : public PlatformSensorMac {
+ public:
+  PlatformSensorAmbientLightMac(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      uint64_t buffer_size,
+      PlatformSensorProvider* provider,
+      const scoped_refptr<base::SingleThreadTaskRunner>&
+          polling_thread_task_runner);
+
+  mojom::ReportingMode GetReportingMode() override;
+  void UpdateReading() override;
+
+ protected:
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+  PlatformSensorConfiguration GetDefaultConfiguration() override;
+
+ private:
+  std::unique_ptr<AmbientLightSensor> platformSensor_;
+  double current_lux;
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorAmbientLightMac);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_MAC_H_