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

device/generic_sensor/platform_sensor_ambient_light_mac.h

+// 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.h"
+
+#include <IOKit/IOKitLib.h>

[Robert Sesek, 2016/09/29 22:51:27]

System includes go first.

+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace device {
+
+class PlatformSensorAmbientLightMac : public PlatformSensor {
+ public:
+  PlatformSensorAmbientLightMac(mojom::SensorType type,
+                                mojo::ScopedSharedBufferMapping mapping,
+                                uint64_t buffer_size,
+                                PlatformSensorProvider* provider);
+
+  mojom::ReportingMode GetReportingMode() override;
+  bool StartSensor(const PlatformSensorConfiguration& configuration) override;
+  void StopSensor() override;
+
+ protected:
+  ~PlatformSensorAmbientLightMac() override;
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+  PlatformSensorConfiguration GetDefaultConfiguration() override;
+  void UpdateReading(uint64_t lux_values[2]);
+
+ private:
+  static void IOServiceCallback(void* context,
+                                io_service_t service,
+                                natural_t message_type,
+                                void*);
+  io_service_t light_sensor_service_;
+  IONotificationPortRef light_sensor_port_;
+  io_object_t light_sensor_object_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
+  double current_lux_;
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorAmbientLightMac);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_PLATFORM_SENSOR_AMBIENT_LIGHT_SENSOR_MAC_H_