make pylint behave the same with or without -v

presubmit_canned_checks.py

 # Copyright (c) 2012 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."""
 
 import os as _os
 _HERE = _os.path.dirname(_os.path.abspath(__file__))
 
 
@@ skipping 657 matching lines @@
       for arg in extra_args:
         child.stdin.write(arg + '\n')
       child.stdin.close()
 
       child.communicate()
       return child.returncode
     except OSError:
       return 'Pylint failed!'
 
   result = None
-  if not input_api.verbose:
+  # Always run pylint and pass it all the py files at once.
+  # Passing py files one at time is slower and can produce
+  # different results.  input_api.verbose used to be used
+  # to enable this behaviour but differing behaviour in
+  # verbose mode is not desirable.
+  if True:
     result = run_lint(sorted(files))
   else:
     for filename in sorted(files):
       print('Running pylint on %s' % filename)
       result = run_lint([filename]) or result
   if isinstance(result, basestring):
     return [error_type(result)]
   elif result:
     return [error_type('Fix pylint errors first.')]
   return []
@@ skipping 265 matching lines @@
     results.extend(input_api.canned_checks.CheckSvnForCommonMimeTypes(
         input_api, output_api))
     snapshot("checking license")
     results.extend(input_api.canned_checks.CheckLicense(
         input_api, output_api, license_header, source_file_filter=sources))
     snapshot("checking was uploaded")
     results.extend(input_api.canned_checks.CheckChangeWasUploaded(
         input_api, output_api))
   snapshot("done")
   return results