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

device/generic_sensor/BUILD.gn

Index: device/generic_sensor/BUILD.gn
diff --git a/device/generic_sensor/BUILD.gn b/device/generic_sensor/BUILD.gn
index 75bed031f0401f23d4c3f4c84449074e987b601c..4b3fc7d7d80580e82993a87b6191a7ab96ecf566 100644
--- a/device/generic_sensor/BUILD.gn
+++ b/device/generic_sensor/BUILD.gn
@@ -10,15 +10,25 @@ if (is_android) {
 
 source_set("generic_sensor") {
   sources = [
+    "ambient_light_mac.cc",
+    "ambient_light_mac.h",
+    "one_writer_seqlock.cc",
+    "one_writer_seqlock.h",
     "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_mac.cc",
+    "platform_sensor_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",
     "sensor_impl.cc",
     "sensor_impl.h",
     "sensor_provider_impl.cc",
@@ -39,6 +49,11 @@ source_set("generic_sensor") {
 
     deps += [ ":jni_headers" ]
   }
+
+  if (is_mac) {
+    sources += []
+    sources -= [ "platform_sensor_provider_default.cc" ]
+  }
 }
 
 if (is_android) {