Update pylintrc to catch more style violations.

PRESUBMIT.py

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import json
 import os
@@ skipping 471 matching lines @@
     r".*objc\.[hcm]+$",
     r"webrtc\/build\/ios\/SDK\/.*",
   )
   source_file_filter = lambda x: input_api.FilterSourceFile(x, None, black_list)
   results.extend(_CheckApprovedFilesLintClean(
       input_api, output_api, source_file_filter))
   results.extend(input_api.canned_checks.RunPylint(input_api, output_api,
       black_list=(r'^base[\\\/].*\.py$',
                   r'^build[\\\/].*\.py$',
                   r'^buildtools[\\\/].*\.py$',
+                  r'^infra[\\\/].*\.py$',
                   r'^ios[\\\/].*\.py$',
                   r'^out.*[\\\/].*\.py$',
                   r'^testing[\\\/].*\.py$',
                   r'^third_party[\\\/].*\.py$',
                   r'^tools[\\\/].*\.py$',
                   # TODO(phoglund): should arguably be checked.
                   r'^tools-webrtc[\\\/]mb[\\\/].*\.py$',
                   r'^tools-webrtc[\\\/]valgrind[\\\/].*\.py$',
                   r'^xcodebuild.*[\\\/].*\.py$',),
-      disabled_warnings=['F0401',  # Failed to import x
-                         'E0611',  # No package y in x
-                         'W0232',  # Class has no __init__ method
-                        ],
       pylintrc='pylintrc'))
 
   # TODO(nisse): talk/ is no more, so make below checks simpler?
   # WebRTC can't use the presubmit_canned_checks.PanProjectChecks function since
   # we need to have different license checks in talk/ and webrtc/ directories.
   # Instead, hand-picked checks are included below.
 
   # .m and .mm files are ObjC files. For simplicity we will consider .h files in
   # ObjC subdirectories ObjC headers.
   objc_filter_list = (r'.+\.m$', r'.+\.mm$', r'.+objc\/.+\.h$')
@@ skipping 45 matching lines @@
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasDescription(
       input_api, output_api))
   results.extend(_CheckChangeHasBugField(input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasTestField(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckTreeIsOpen(
       input_api, output_api,
       json_url='http://webrtc-status.appspot.com/current?format=json'))
   return results