Remove DeviceLightEvent implementation

device/sensors/public/cpp/device_util_mac.h

Index: device/sensors/public/cpp/device_util_mac.h
diff --git a/device/sensors/public/cpp/device_util_mac.h b/device/sensors/public/cpp/device_util_mac.h
deleted file mode 100644
index 82c728af5d4e967b3cea3ba8f8f0807ef49d1495..0000000000000000000000000000000000000000
--- a/device/sensors/public/cpp/device_util_mac.h
+++ /dev/null
@@ -1,18 +0,0 @@
-// 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_SENSORS_PUBLIC_CPP_DEVICE_UTIL_MAC_H_
-#define DEVICE_SENSORS_PUBLIC_CPP_DEVICE_UTIL_MAC_H_
-
-#include <stdint.h>
-
-namespace device {
-
-// Convert the value returned by the ambient light LMU sensor on Mac
-// hardware to a lux value.
-double LMUvalueToLux(uint64_t raw_value);
-
-}  // namespace device
-
-#endif  // DEVICE_SENSORS_PUBLIC_CPP_DEVICE_UTIL_MAC_H_