Run pychecker over most scripts in depot_tools. Catched a few bugs.

presubmit_canned_checks.py

 #!/usr/bin/env 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.
 
 """Generic presubmit checks that can be reused by other presubmit checks."""
 
 
 ### Description checks
 
@@ skipping 244 matching lines @@
 
 
 def CheckSvnProperty(input_api, output_api, prop, expected, affected_files):
   """Checks that affected_files files have prop=expected."""
   if input_api.change.scm != 'svn':
     return []
 
   bad = filter(lambda f: f.Property(prop) != expected, affected_files)
   if bad:
     if input_api.is_committing:
-      type = output_api.PresubmitError
+      res_type = output_api.PresubmitError
     else:
-      type = output_api.PresubmitNotifyResult
+      res_type = output_api.PresubmitNotifyResult
     message = "Run `svn pset %s %s <item>` on these files:" % (prop, expected)
-    return [type(message, items=bad)]
+    return [res_type(message, items=bad)]
   return []
 
 
 ### Other checks
 
 def CheckDoNotSubmit(input_api, output_api):
   return (
       CheckDoNotSubmitInDescription(input_api, output_api) +
       CheckDoNotSubmitInFiles(input_api, output_api)
       )
@@ skipping 62 matching lines @@
         stderr=input_api.subprocess.PIPE)
     stdoutdata, stderrdata = subproc.communicate()
     # Discard the output if returncode == 0
     if subproc.returncode:
       outputs.append("Test '%s' failed with code %d\n%s\n%s\n" % (
           unit_test_name, subproc.returncode, stdoutdata, stderrdata))
   if outputs:
     return [message_type("%d unit tests failed." % len(outputs),
                                 long_text='\n'.join(outputs))]
   return []