Remove code duplication and improve style.

gcl.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 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.
 
 """\
 Wrapper script around Rietveld's upload.py that simplifies working with groups
 of files.
 """
 
@@ skipping 186 matching lines @@
   print >> sys.stderr, msg
 
 
 def ErrorExit(msg):
   print >> sys.stderr, msg
   sys.exit(1)
 
 
 def RunShellWithReturnCode(command, print_output=False):
   """Executes a command and returns the output and the return code."""
-  # Use a shell for subcommands on Windows to get a PATH search, and because svn
-  # may be a batch file.
-  use_shell = sys.platform.startswith("win")
-  env = os.environ.copy()
-  env['LANGUAGE'] = 'en'
-  p = subprocess.Popen(command, stdout=subprocess.PIPE,
-                       stderr=subprocess.STDOUT, shell=use_shell, env=env,
-                       universal_newlines=True)
+  p = gclient_utils.Popen(command, stdout=subprocess.PIPE,
+                          stderr=subprocess.STDOUT, universal_newlines=True)
   if print_output:
     output_array = []
     while True:
       line = p.stdout.readline()
       if not line:
         break
       if print_output:
         print line.strip('\n')
       output_array.append(line)
     output = "".join(output_array)
@@ skipping 1091 matching lines @@
     if command:
       return command(argv[1:])
     # Unknown command, try to pass that to svn
     return CMDpassthru(argv)
   except gclient_utils.Error, e:
     print('Got an exception')
     print(str(e))
 
 if __name__ == "__main__":
   sys.exit(main(sys.argv[1:]))