Fix regression in chrome_proxy tests caused by switching to typ.

tools/chrome_proxy/run_tests

 #!/usr/bin/env python
 # Copyright 2014 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 script runs unit tests of the code in the perf directory.
 
 This script DOES NOT run benchmarks. run_benchmark does that.
 """
 
 import os
 import subprocess
 import sys
 
 
 if __name__ == '__main__':
   proxy_dir = os.path.dirname(os.path.realpath(__file__))
+  perf_dir = os.path.realpath(os.path.join(proxy_dir, '..', 'perf'))
   telemetry_dir = os.path.realpath(os.path.join(proxy_dir, '..', 'telemetry'))
 
   env = os.environ.copy()
   if 'PYTHONPATH' in env:
     env['PYTHONPATH'] = env['PYTHONPATH'] + os.pathsep + telemetry_dir
   else:
     env['PYTHONPATH'] = telemetry_dir
 
   path_to_run_tests = os.path.join(telemetry_dir, 'telemetry', 'unittest_util',
                                    'run_tests.py')
-  argv = ['--top-level-dir', proxy_dir] + sys.argv[1:]
+  argv = ['--top-level-dir', proxy_dir, '--path', perf_dir] + sys.argv[1:]
   sys.exit(subprocess.call([sys.executable, path_to_run_tests] + argv, env=env))