[Telemetry] Add timeout to telemetry run_tests

tools/telemetry/run_tests

 #!/usr/bin/env python
 # Copyright (c) 2012 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 os
 import sys
-import subprocess
+
+TELEMETRY_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.append(os.path.join(TELEMETRY_DIR, 'third_party', 'subprocess32'))
+import subprocess32
 
 
 if __name__ == '__main__':
-  telemetry_dir = os.path.dirname(os.path.realpath(__file__))
 
   env = os.environ.copy()
   if 'PYTHONPATH' in env:
-    env['PYTHONPATH'] = env['PYTHONPATH'] + os.pathsep + telemetry_dir
+    env['PYTHONPATH'] = env['PYTHONPATH'] + os.pathsep + TELEMETRY_DIR
   else:
-    env['PYTHONPATH'] = telemetry_dir
+    env['PYTHONPATH'] = TELEMETRY_DIR
 
-  path_to_run_tests = os.path.join(telemetry_dir, 'telemetry', 'testing',
+  path_to_run_tests = os.path.join(TELEMETRY_DIR, 'telemetry', 'testing',
                                    'run_tests.py')
-  argv = ['--top-level-dir', telemetry_dir] + sys.argv[1:]
-  sys.exit(subprocess.call([sys.executable, path_to_run_tests] + argv, env=env))
+  argv = ['--top-level-dir', TELEMETRY_DIR] + sys.argv[1:]
+  # Timeout test run after 10 minutes.
+  sys.exit(subprocess32.call(
+      [sys.executable, path_to_run_tests] + argv, env=env, timeout=600))