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

device/generic_sensor/BUILD.gn

 # 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.
 
 source_set("generic_sensor") {
   sources = [
     "platform_sensor.cc",
     "platform_sensor.h",
+    "platform_sensor_ambient_light_mac.cc",
+    "platform_sensor_ambient_light_mac.h",
+    "platform_sensor_android.cc",
+    "platform_sensor_android.h",
+    "platform_sensor_configuration_android.cc",
+    "platform_sensor_configuration_android.h",
+    "platform_sensor_mac.h",
+    "platform_sensor_polling_mac.cc",
+    "platform_sensor_polling_mac.h",
     "platform_sensor_provider.h",
+    "platform_sensor_provider_android.cc",
     "platform_sensor_provider_base.cc",
     "platform_sensor_provider_base.h",
     "platform_sensor_provider_default.cc",
+    "platform_sensor_provider_mac.cc",
+    "platform_sensor_provider_mac.h",
+    "platform_sensor_util_mac.cc",
+    "platform_sensor_util_mac.h",
     "sensor_impl.cc",
     "sensor_impl.h",
     "sensor_provider_impl.cc",
     "sensor_provider_impl.h",
   ]
 
   deps = [
     "//base",
     "//device/generic_sensor/public/interfaces",
   ]
+
+  if (is_mac) {
+    sources += []
+    sources -= [ "platform_sensor_provider_default.cc" ]
+  }
 }