Remove DeviceLightEvent implementation

device/sensors/public/cpp/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.
 
 # This target contains only those files that are shared by the Device Sensors
 # implementation and all Device Sensors clients, including Blink. Add a file
 # here only if it meets the following constraints:
 # (1) It is *necessary* to use the file to consume Device Sensors (the
 # current files define structs that are used as a consistent interpretation of
 # shared memory by the Device Sensor and its clients).
@@ skipping 14 matching lines @@
     "orientation_data.h",
   ]
   # Do not add deps here per the above comment.
 }
 
 # This target is a superset of the above one that contains additional optional
 # files available to Device Sensors clients. This target may bring in
 # dependencies on the STL and Chromium code.
 source_set("full") {
   sources = [
-    "device_light_data.h",
-    "device_light_hardware_buffer.h",
     "device_motion_hardware_buffer.h",
     "device_orientation_hardware_buffer.h",
-    "device_sensors_consts.h",
-    "device_util_mac.cc",
-    "device_util_mac.h",
   ]
 
   public_deps = [
     ":shared_with_blink",
     "//device/base/synchronization",
   ]
 }