[Mac/GN] Add verify_order step for the Framework.

chrome/tools/build/mac/run_verify_order.py

 # 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.
 
 import argparse
-import os
+import os.path
+import sys
 import subprocess
-import sys
+
+# Wraps chrome/tools/build/mac/verify_order for the GN build so that it can
+# write a stamp file, rather than operate as a postbuild.
 
 if __name__ == '__main__':
   parser = argparse.ArgumentParser(
-      description='A script to execute a command via xcrun.')
+      description='A wrapper around verify_order that writes a stamp file.')
   parser.add_argument('--stamp', action='store', type=str,
-      help='Write a stamp file to this path on success.')
+      help='Touch this stamp file on success.')
+
   args, unknown_args = parser.parse_known_args()
 
-  rv = subprocess.check_call(['xcrun'] + unknown_args)
+  this_script_dir = os.path.dirname(sys.argv[0])
+  rv = subprocess.check_call(
+      [ os.path.join(this_script_dir, 'verify_order') ] + unknown_args)
+
   if rv == 0 and args.stamp:
     if os.path.exists(args.stamp):
       os.unlink(args.stamp)
     open(args.stamp, 'w+').close()
 
   sys.exit(rv)