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

device/generic_sensor/platform_sensor.cc

 // 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.
 
 #include "device/generic_sensor/platform_sensor.h"
 
 #include <utility>
 
 #include "device/generic_sensor/platform_sensor_provider.h"
 #include "device/generic_sensor/public/cpp/platform_sensor_configuration.h"
 
 namespace device {
 
 PlatformSensor::PlatformSensor(mojom::SensorType type,
                                mojo::ScopedSharedBufferMapping mapping,
                                PlatformSensorProvider* provider)
     : shared_buffer_mapping_(std::move(mapping)),
+      provider_(provider),
       type_(type),
-      provider_(provider),
       weak_factory_(this) {}
 
 PlatformSensor::~PlatformSensor() {
   provider_->RemoveSensor(GetType());
 }
 
 mojom::SensorType PlatformSensor::GetType() const {
   return type_;
 }
 
@@ skipping 58 matching lines @@
     if (!client->IsNotificationSuspended())
       client->OnSensorReadingChanged();
   }
 }
 
 void PlatformSensor::NotifySensorError() {
   FOR_EACH_OBSERVER(Client, clients_, OnSensorError());
 }
 
 }  // namespace device