Add nag_timer.

tests/subprocess2_test.py

 #!/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.
 
 """Unit tests for subprocess2.py."""
 
 import logging
 import optparse
 import os
@@ skipping 573 matching lines @@
       pass
     def blow(_):
       raise Blow()
     proc = subprocess2.Popen(self.exe + ['--stdout'], stdout=blow)
     try:
       proc.communicate()
       self.fail()
     except Blow:
       self.assertNotEquals(0, proc.returncode)
 
+  def test_nag_timer(self):
+    w = []
+    l = logging.getLogger()
+    class _Filter(logging.Filter):
+      def filter(self, record):
+        if record.levelno == logging.WARNING:
+          w.append(record.getMessage().lstrip())
+        return 0
+    f = _Filter()
+    l.addFilter(f)
+    proc = subprocess2.Popen(
+        self.exe + ['--stdout', '--sleep_first'], stdout=PIPE)
+    res = proc.communicate(nag_timer=3), proc.returncode
+    l.removeFilter(f)
+    self._check_res(res, 'A\nBB\nCCC\n', None, 0)
+    expected = ['No output for 3 seconds from command:', proc.cmd_str,
+                'No output for 6 seconds from command:', proc.cmd_str,
+                'No output for 9 seconds from command:', proc.cmd_str]
+    self.assertEquals(w, expected)
 
+    
 def child_main(args):
   if sys.platform == 'win32':
     # Annoying, make sure the output is not translated on Windows.
     # pylint: disable=E1101,F0401
     import msvcrt
     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
     msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
 
   parser = optparse.OptionParser()
   parser.add_option(
@@ skipping 45 matching lines @@
   return options.return_value
 
 
 if __name__ == '__main__':
   logging.basicConfig(level=
       [logging.WARNING, logging.INFO, logging.DEBUG][
         min(2, sys.argv.count('-v'))])
   if len(sys.argv) > 1 and sys.argv[1] == '--child':
     sys.exit(child_main(sys.argv[2:]))
   unittest.main()