Add --quiet option.

git_cache.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """A git command for managing a local cache of git repositories."""
 
 from __future__ import print_function
 import errno
 import logging
@@ skipping 478 matching lines @@
         unlocked_repos))
 
 
 class OptionParser(optparse.OptionParser):
   """Wrapper class for OptionParser to handle global options."""
 
   def __init__(self, *args, **kwargs):
     optparse.OptionParser.__init__(self, *args, prog='git cache', **kwargs)
     self.add_option('-c', '--cache-dir',
                     help='Path to the directory containing the cache')
-    self.add_option('-v', '--verbose', action='count', default=0,
+    self.add_option('-v', '--verbose', action='count', default=1,
                     help='Increase verbosity (can be passed multiple times)')
+    self.add_option('-q', '--quiet', action='store_true',
+                    help='Suppress all extraneous output')
 
   def parse_args(self, args=None, values=None):
     options, args = optparse.OptionParser.parse_args(self, args, values)
+    if options.quiet:
+      options.verbose = 0
+
+    levels = [logging.ERROR, logging.WARNING, logging.INFO, logging.DEBUG]
+    logging.basicConfig(level=levels[min(options.verbose, len(levels) - 1)])
 
     try:
       global_cache_dir = Mirror.GetCachePath()
     except RuntimeError:
       global_cache_dir = None
     if options.cache_dir:
       if global_cache_dir and (
           os.path.abspath(options.cache_dir) !=
           os.path.abspath(global_cache_dir)):
         logging.warn('Overriding globally-configured cache directory.')
       Mirror.SetCachePath(options.cache_dir)
 
-    levels = [logging.WARNING, logging.INFO, logging.DEBUG]
-    logging.basicConfig(level=levels[min(options.verbose, len(levels) - 1)])
-
     return options, args
 
 
 def main(argv):
   dispatcher = subcommand.CommandDispatcher(__name__)
   return dispatcher.execute(OptionParser(), argv)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))