Fix presubmit errors in toolchain2013, so that cq works for depot_tools.

depot_tools/win_toolchain/toolchain2013.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.
 
 """Extracts a Windows VS2013 toolchain from various downloadable pieces."""
 
 
 import ctypes
 import optparse
@@ skipping 19 matching lines @@
 
 
 def RunOrDie(command):
   subprocess.check_call(command, shell=True)
 
 
 def TempDir():
   """Generates a temporary directory (for downloading or extracting to) and keep
   track of the directory that's created for cleaning up later.
   """
-  global g_temp_dirs
   temp = tempfile.mkdtemp()
   g_temp_dirs.append(temp)
   return temp
 
 
 def DeleteAllTempDirs():
   """Removes all temporary directories created by |TempDir()|."""
   global g_temp_dirs
   if g_temp_dirs:
     sys.stdout.write('Cleaning up temporaries...\n')
@@ skipping 19 matching lines @@
 
 def Download(url, local_path):
   """Downloads a large-ish binary file and print some status information while
   doing so.
   """
   sys.stdout.write('Downloading %s...\n' % url)
   req = urllib2.urlopen(url)
   content_length = int(req.headers.get('Content-Length', 0))
   bytes_read = 0L
   terminator = '\r' if sys.stdout.isatty() else '\n'
-  with open(local_path, 'wb') as file:
+  with open(local_path, 'wb') as file_handle:
     while True:
       chunk = req.read(1024 * 1024)
       if not chunk:
         break
       bytes_read += len(chunk)
-      file.write(chunk)
+      file_handle.write(chunk)
       sys.stdout.write('... %d/%d%s' % (bytes_read, content_length, terminator))
       sys.stdout.flush()
   sys.stdout.write('\n')
   if content_length and content_length != bytes_read:
     raise SystemExit('Got incorrect number of bytes downloading %s' % url)
 
 
 def ExtractIso(iso_path):
   """Uses 7zip to extract the contents of the given .iso (or self-extracting
   .exe).
@@ skipping 77 matching lines @@
 def CopyToFinalLocation(extracted_dirs, target_dir):
   sys.stdout.write('Copying to final location...\n')
   mappings = {
       'Program Files\\Microsoft Visual Studio 12.0\\': '.\\',
       'System64\\': 'sys64\\',
       'System\\': 'sys32\\',
       'Windows Kits\\8.0\\': 'win8sdk\\',
   }
   matches = []
   for extracted_dir in extracted_dirs:
-    for root, dirnames, filenames in os.walk(extracted_dir):
+    for root, _, filenames in os.walk(extracted_dir):
       for filename in filenames:
         matches.append((extracted_dir, os.path.join(root, filename)))
 
   copies = []
   for prefix, full_path in matches:
     # +1 for trailing \.
     partial_path = full_path[len(prefix) + 1:]
     for map_from, map_to in mappings.iteritems():
       if partial_path.startswith(map_from):
         target_path = os.path.join(map_to, partial_path[len(map_from):])
@@ skipping 63 matching lines @@
   parser.add_option('--targetdir', metavar='DIR',
                     help='put toolchain into DIR',
                     default=os.path.join(BASEDIR, 'win_toolchain_2013'))
   parser.add_option('--noclean', action='store_false', dest='clean',
                     help='do not remove temp files',
                     default=True)
   parser.add_option('--local', metavar='DIR',
                     help='use downloaded files from DIR')
   parser.add_option('--express',
                     help='use VS Express instead of Pro', action='store_true')
-  options, args = parser.parse_args()
+  options, _ = parser.parse_args()
   try:
     target_dir = os.path.abspath(options.targetdir)
     if os.path.exists(target_dir):
       parser.error('%s already exists. Please [re]move it or use '
                    '--targetdir to select a different target.\n' %
                    target_dir)
     # Set the working directory to 7z subdirectory. 7-zip doesn't find its
     # codec dll very well, so this is the simplest way to make sure it runs
     # correctly, as we don't otherwise care about working directory.
     os.chdir(os.path.join(BASEDIR, '7z'))
     image = GetSourceImage(options.local, not options.express)
     extracted = ExtractComponents(image)
     CopyToFinalLocation(extracted, target_dir)
 
     GenerateSetEnvCmd(target_dir, not options.express)
   finally:
     if options.clean:
       DeleteAllTempDirs()
 
 
 if __name__ == '__main__':
   sys.exit(main())