Style cleanup in auxiliary bisect-related scripts.

tools/run-bisect-manual-test.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.
 
 """Run Manual Test Bisect Tool
 
 An example usage:
 tools/run-bisect-manual-test.py -g 201281 -b 201290
 
 On Linux platform, follow the instructions in this document
 https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment
 to setup the sandbox manually before running the script. Otherwise the script
 fails to launch Chrome and exits with an error.
 
+This script serves a similar function to bisect-builds.py, except it uses
+the bisect-perf-regression.py. This means that that it can actually check out
+and build revisions of Chromium that are not available in cloud storage.
 """
 
 import os
 import subprocess
 import sys
 
 CROS_BOARD_ENV = 'BISECT_CROS_BOARD'
 CROS_IP_ENV = 'BISECT_CROS_IP'
 _DIR_TOOLS_ROOT = os.path.abspath(os.path.dirname(__file__))
 
 sys.path.append(os.path.join(_DIR_TOOLS_ROOT, 'telemetry'))
 from telemetry.core import browser_options
 
 
 def _RunBisectionScript(options):
-  """Attempts to execute src/tools/bisect-perf-regression.py with the parameters
-  passed in.
+  """Attempts to execute src/tools/bisect-perf-regression.py.
 
   Args:
     options: The configuration options to pass to the bisect script.
 
   Returns:
-    0 on success, otherwise 1.
+    The exit code of bisect-perf-regression.py: 0 on success, otherwise 1.
   """
-  test_command = 'python %s --browser=%s --chrome-root=.' %\
-      (os.path.join(_DIR_TOOLS_ROOT, 'bisect-manual-test.py'),
-       options.browser_type)
+  test_command = ('python %s --browser=%s --chrome-root=.' %
+                  (os.path.join(_DIR_TOOLS_ROOT, 'bisect-manual-test.py'),
+                   options.browser_type))
 
   cmd = ['python', os.path.join(_DIR_TOOLS_ROOT, 'bisect-perf-regression.py'),
          '-c', test_command,
          '-g', options.good_revision,
          '-b', options.bad_revision,
          '-m', 'manual_test/manual_test',
          '-r', '1',
          '--working_directory', options.working_directory,
          '--build_preference', 'ninja',
          '--use_goma',
          '--no_custom_deps']
 
   if options.extra_src:
     cmd.extend(['--extra_src', options.extra_src])
 
   if 'cros' in options.browser_type:
     cmd.extend(['--target_platform', 'cros'])
 
     if os.environ[CROS_BOARD_ENV] and os.environ[CROS_IP_ENV]:
       cmd.extend(['--cros_board', os.environ[CROS_BOARD_ENV]])
       cmd.extend(['--cros_remote_ip', os.environ[CROS_IP_ENV]])
     else:
-      print 'Error: Cros build selected, but BISECT_CROS_IP or'\
-            'BISECT_CROS_BOARD undefined.'
-      print
+      print ('Error: Cros build selected, but BISECT_CROS_IP or'
+             'BISECT_CROS_BOARD undefined.\n')
       return 1
   elif 'android-chrome' in options.browser_type:
     cmd.extend(['--target_platform', 'android-chrome'])
   elif 'android' in options.browser_type:
     cmd.extend(['--target_platform', 'android'])
   elif not options.target_build_type:
     cmd.extend(['--target_build_type', options.browser_type.title()])
 
   if options.target_build_type:
     cmd.extend(['--target_build_type', options.target_build_type])
 
-
   cmd = [str(c) for c in cmd]
 
   return_code = subprocess.call(cmd)
 
   if return_code:
-    print 'Error: bisect-perf-regression.py returned with error %d' %\
-        return_code
+    print ('Error: bisect-perf-regression.py returned with error %d' %
+           return_code)
     print
 
   return return_code
 
 
 def main():
+  """Does a bisect based on the command-line arguments passed in.
+
+  The user will be prompted to classify each revision as good or bad.
+  """
   usage = ('%prog [options]\n'
            'Used to run the bisection script with a manual test.')
 
   options = browser_options.BrowserFinderOptions('release')
   parser = options.CreateParser(usage)
 
   parser.add_option('-b', '--bad_revision',
                     type='str',
                     help='A bad revision to start bisection. ' +
                     'Must be later than good revision. May be either a git' +
@@ skipping 11 matching lines @@
                     'a copy of the chromium depot.')
   parser.add_option('--extra_src',
                     type='str',
                     help='Path to extra source file. If this is supplied, '
                     'bisect script will use this to override default behavior.')
   parser.add_option('--target_build_type',
                      type='choice',
                      choices=['Release', 'Debug'],
                      help='The target build type. Choices are "Release" '
                      'or "Debug".')
-  options, args = parser.parse_args()
+  options, _ = parser.parse_args()
   error_msg = ''
   if not options.good_revision:
     error_msg += 'Error: missing required parameter: --good_revision\n'
   if not options.bad_revision:
     error_msg += 'Error: missing required parameter: --bad_revision\n'
 
   if error_msg:
     print error_msg
     parser.print_help()
     return 1
 
   if 'android' not in options.browser_type and sys.platform.startswith('linux'):
     if not os.environ.get('CHROME_DEVEL_SANDBOX'):
       print 'SUID sandbox has not been setup.'\
             ' See https://code.google.com/p/chromium/wiki/'\
             'LinuxSUIDSandboxDevelopment for more information.'
       return 1
 
   return _RunBisectionScript(options)
 
 
 if __name__ == '__main__':
   sys.exit(main())