Gathering information about test filter files into a README.md file.

build/android/test_runner.py

 #!/usr/bin/env python
 #
 # Copyright 2013 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.
 
 """Runs all types of tests from one unified interface."""
 
 import argparse
 import collections
@@ skipping 278 matching lines @@
                      action='store_true',
                      help=argparse.SUPPRESS)
 
   filter_group = group.add_mutually_exclusive_group()
   filter_group.add_argument('-f', '--gtest_filter', '--gtest-filter',
                             dest='test_filter',
                             help='googletest-style filter string.')
   filter_group.add_argument('--gtest-filter-file', dest='test_filter_file',
                             type=os.path.realpath,
                             help='Path to file that contains googletest-style '
-                                  'filter strings. (Lines will be joined with '
-                                  '":" to create a single filter string.)')
+                                  'filter strings.  See also '
+                                  '//testing/buildbot/filters/README.md.')
 
   AddDeviceOptions(parser)
   AddCommonOptions(parser)
   AddRemoteDeviceOptions(parser)
 
 
 def AddLinkerTestOptions(parser):
   group = parser.add_argument_group('Linker Test Options')
   group.add_argument('-f', '--gtest-filter', dest='test_filter',
                      help='googletest-style filter string.')
@@ skipping 641 matching lines @@
     if e.is_infra_error:
       return constants.INFRA_EXIT_CODE
     return constants.ERROR_EXIT_CODE
   except: # pylint: disable=W0702
     logging.exception('Unrecognized error occurred.')
     return constants.ERROR_EXIT_CODE
 
 
 if __name__ == '__main__':
   sys.exit(main())