Delete several unused GYP scripts from build/mac and chrome/tools/build/mac.

chrome/tools/mac_helpers/lipo_thin_x86_64.sh

Index: chrome/tools/mac_helpers/lipo_thin_x86_64.sh
diff --git a/chrome/tools/mac_helpers/lipo_thin_x86_64.sh b/chrome/tools/mac_helpers/lipo_thin_x86_64.sh
deleted file mode 100755
index 1687e37b2a5e1bbb2f3c19be1a7e9bc2a9b5f25e..0000000000000000000000000000000000000000
--- a/chrome/tools/mac_helpers/lipo_thin_x86_64.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-
-# Copyright 2015 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 uses lipo to thin out the specified file.
-
-set -e
-
-if [ $# -ne 1 ] ; then
-  echo "usage: ${0} FILEPATH" >& 2
-  exit 1
-fi
-
-FILEPATH="${1}"
-
-lipo -thin x86_64 "${FILEPATH}" -o "${FILEPATH}"