Add disabled_warnings arg to RunPylint() and use the default pylintrc file by default.

tests/presubmit_unittest.py

Index: tests/presubmit_unittest.py
diff --git a/tests/presubmit_unittest.py b/tests/presubmit_unittest.py
index 29f9a931007a3846d9fbb61991a0525f07b3db34..75d140ada80207cfd63a2de4f54ccc2b73211391 100755
--- a/tests/presubmit_unittest.py
+++ b/tests/presubmit_unittest.py
@@ -13,6 +13,9 @@ import StringIO
 import sys
 import time
 
+# TODO(maruel): Include inside depot_tools.
+from pylint import lint
+
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 from testing_support.super_mox import mox, SuperMoxTestBase
@@ -1449,6 +1452,7 @@ class CannedChecksUnittest(PresubmitTestsBase):
     input_api = self.mox.CreateMock(presubmit.InputApi)
     input_api.cStringIO = presubmit.cStringIO
     input_api.json = presubmit.json
+    input_api.logging = logging
     input_api.os_listdir = self.mox.CreateMockAnything()
     input_api.os_walk = self.mox.CreateMockAnything()
     input_api.os_path = presubmit.os.path
@@ -1462,6 +1466,7 @@ class CannedChecksUnittest(PresubmitTestsBase):
       def __str__(self):
         return 'foo'
     input_api.subprocess.CalledProcessError = fake_CalledProcessError
+    input_api.verbose = False
 
     input_api.change = change
     input_api.host_url = 'http://localhost'
@@ -2130,6 +2135,20 @@ class CannedChecksUnittest(PresubmitTestsBase):
         input_api, presubmit.OutputApi, ['test_module'])
     self.assertEquals(len(results), 0)
 
+  def testCannedRunPylint(self):
+    # lint.Run() always calls sys.exit()...
+    lint.Run = lambda x: sys.exit(0)
+    input_api = self.MockInputApi(None, True)
+    input_api.AffectedSourceFiles(mox.IgnoreArg()).AndReturn(True)
+    input_api.PresubmitLocalPath().AndReturn('/foo')
+    input_api.PresubmitLocalPath().AndReturn('/foo')
+    input_api.os_walk('/foo').AndReturn([('/foo', [], ['file1.py'])])
+    self.mox.ReplayAll()
+
+    results = presubmit_canned_checks.RunPylint(
+        input_api, presubmit.OutputApi)
+    self.assertEquals([], results)
+
   def testCheckBuildbotPendingBuildsBad(self):
     input_api = self.MockInputApi(None, True)
     connection = self.mox.CreateMockAnything()