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

device/generic_sensor/platform_sensor.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_SENSOR_PLATFORM_SENSOR_H_
 #define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_H_
 
 #include <list>
 #include <map>
 
@@ skipping 47 matching lines @@
   using ConfigMap = std::map<Client*, std::list<PlatformSensorConfiguration>>;
 
   virtual bool UpdateSensorInternal(const ConfigMap& configurations) = 0;
   virtual bool CheckSensorConfiguration(
       const PlatformSensorConfiguration& configuration) = 0;
 
   void NotifySensorReadingChanged();
   void NotifySensorError();
 
   mojo::ScopedSharedBufferMapping shared_buffer_mapping_;
+  PlatformSensorProvider* provider_;
 
  private:
   friend class base::RefCountedThreadSafe<PlatformSensor>;
 
   mojom::SensorType type_;
   base::ObserverList<Client, true> clients_;
   ConfigMap config_map_;
-  PlatformSensorProvider* provider_;
   base::WeakPtrFactory<PlatformSensor> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(PlatformSensor);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_H_