Fix gtest-parallel-wrapper

tools_webrtc/gtest-parallel-wrapper.py

 #!/usr/bin/env python
 
 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
@@ skipping 46 matching lines @@
 
 def CatFiles(file_list, output_file):
   with open(output_file, 'w') as output_file:
     for filename in file_list:
       with open(filename) as input_file:
         output_file.write(input_file.read())
       os.remove(filename)
 
 
 def get_args_and_env():
-  if '--' not in sys.argv:
-    return sys.argv, os.environ
-
-  argv_index = sys.argv.index('--')
+  if '--' in sys.argv:
+    argv_index = sys.argv.index('--')
+  else:
+    argv_index = len(sys.argv)
 
   gtest_parallel_args = sys.argv[1:argv_index]
   executable_args = sys.argv[argv_index + 1:]
 
   parser = argparse.ArgumentParser()
   parser.add_argument('--isolated-script-test-output', type=str, default=None)
 
   # We don't need to implement this flag, and possibly can't, since it's
   # intended for results of Telemetry tests. See
   # https://chromium.googlesource.com/external/github.com/catapult-project/catapult/+/HEAD/dashboard/docs/data-format.md
@@ skipping 64 matching lines @@
       logs = [os.path.join(logs_dir, log) for log in os.listdir(logs_dir)]
       log_file = os.path.join(output_dir, '%s-tests.log' % test_status)
       CatFiles(logs, log_file)
       os.rmdir(logs_dir)
 
   return exit_code
 
 
 if __name__ == '__main__':
   sys.exit(main())