[content/test/gpu] Run pylint check of gpu tests in unittest instead of PRESUBMIT

third_party/pylint/README.chromium

+URL: http://www.pylint.org/
+Name: pylint
+Version: 1.4.1
+License: GPL v2
+License File: pylint/LICENSE.txt
+Security Critical: No
+
+Description:
+This directory contains the pylint module.
+
+Local Modifications:
+- applied upstream fix https://bitbucket.org/logilab/pylint/commits/5df347467ee0
+- applied fix to work around bad interaction between sys.path manipulation in
+  pylint itself and multiprocessing's implementation on Windows (DIFF1)
+
+
+Diffs:
+DIFF1
+diff --git a/third_party/pylint/lint.py b/third_party/pylint/lint.py
+index e10ae56..082d8b3 100644
+--- a/third_party/pylint/lint.py
++++ b/third_party/pylint/lint.py
+@@ -671,7 +671,8 @@ class PyLinter(configuration.OptionsManagerMixIn,
+             files_or_modules = (files_or_modules,)
+
+         if self.config.jobs == 1:
+-            self._do_check(files_or_modules)
++            with fix_import_path(files_or_modules):
++                self._do_check(files_or_modules)
+         else:
+             # Hack that permits running pylint, on Windows, with -m switch
+             # and with --jobs, as in 'python -2 -m pylint .. --jobs'.
+@@ -1252,8 +1253,8 @@ group are mutually exclusive.'),
+
+         # insert current working directory to the python path to have a correct
+         # behaviour
+-        with fix_import_path(args):
+-            if self.linter.config.profile:
++        if self.linter.config.profile:
++            with fix_import_path(args):
+                 print('** profiled run', file=sys.stderr)
+                 import cProfile, pstats
+                 cProfile.runctx('linter.check(%r)' % args, globals(), locals(),
+@@ -1262,9 +1263,9 @@ group are mutually exclusive.'),
+                 data.strip_dirs()
+                 data.sort_stats('time', 'calls')
+                 data.print_stats(30)
+-            else:
+-                linter.check(args)
+-            linter.generate_reports()
++        else:
++            linter.check(args)
++        linter.generate_reports()
+         if exit:
+             sys.exit(self.linter.msg_status)