Simplify mojo_shell since it's now only used for Mandoline.

mojo/tools/apptest_runner.py

 #!/usr/bin/env python
 # 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.
 
 """A test runner for gtest application tests."""
 
 import argparse
 import ast
 import logging
@@ skipping 41 matching lines @@
     # TODO(msw): Run some apptests without fixture isolation?
     fixtures = gtest.get_fixtures(mojo_shell_path, apptest)
 
     if not fixtures:
       print "Failed with no tests found."
       exit_code = 1
       continue
 
     apptest_result = "Succeeded"
     for fixture in fixtures:
-      args_for_apptest = " ".join(["--args-for=" + apptest,
-                                   "--gtest_filter=" + fixture] + apptest_args)
+      args_for_apptest = " ".join(["--gtest_filter=" + fixture] + apptest_args)
 
       success = RunApptestInShell(mojo_shell_path, apptest,
                                   shell_args + [args_for_apptest])
 
       if not success:
         apptest_result = "Failed test(s) in %r" % apptest_dict
         exit_code = 1
 
     print apptest_result
 
   return exit_code
 
 
 def RunApptestInShell(mojo_shell_path, apptest, shell_args):
   return gtest.run_test([mojo_shell_path, apptest] + shell_args)
 
 
 if __name__ == '__main__':
   sys.exit(main())